I really wish to know with sources what are the benefits or rewards of observing Shabbat and what are the punishments for someone who desecrates it. Furthermore, what are the disadvantages of being a Mekhalel Shabbat from different sources? (For example, Chacham Ovadia says a Mekhalel shabbat can be lent money with interest)
DailyHalacha has a nice summary based on the Tur on SA OC 242
The Tur cites a number of passages from the Talmud that underscore the importance of observing and enjoying Shabbat:
1) One who observes Shabbat as a day of enjoyment and delight is rewarded with a "portion without boundaries," meaning, unlimited blessings. Just as he spent money freely for the purpose of honoring Shabbat, so is he rewarded with unlimited blessing.
2) A person who properly observes Shabbat is spared subjugation and oppression by foreign governments. Since he has joyfully accepted upon himself God's kingship through the careful observance of Shabbat, he will not have to endure subjugation to any other authority.
3) Whoever observes Shabbat as a day of enjoyment and delight is granted all the wishes of his heart. Just as he enjoyed the Shabbat, so will God grant him what he needs to always experience joy and contentment.
4) Whoever properly observes Shabbat earns atonement for his misdeeds, even if he worshipped foreign gods.
R Eliezer Melamed (Peninei Halakha Shabbat 1:14) describes the punishment for the desecration of Shabbat
if one intentionally desecrates Shabbat in front of witnesses who forewarned him, he is liable for death by stoning. If no witnesses were present, but the violation is intentional, he is subject to karet (extirpation), as it is written: “You shall keep Shabbat, for it is holy for you. He who profanes it shall be put to death; whoever does work on it shall be cut off (ve-nikhreta) from among his people” (Shemot 31:14). In actuality, almost no one was ever put to death, as it was rare for all the conditions that would mandate the death penalty to be met.
The severity of Shabbat desecration can also be seen in Zohar, which states that during Shabbat, the fires of Hell stop consuming the wicked, with the exception of those wicked who never observed Shabbat (Zohar II 151:1). However, one who repented – and certainly one who was already punished for his sin, like the wood gatherer – is forgiven and not punished in Hell.
THE GREAT REWARD AND GLORY PROMISED TO HIM WHO SANCTIFIES THE HOLINESS OF SHABBAT AND THE PUNISHMENT TO HIM WHO DESECRATES THE SHABBAT
THE PUNISHMENTS FOR THE TRANSGRESSORS
1) "To fear the L-rd your G-d all your days"- This refers to Shabbat and festivals (Yevamoth 93).
2) "Fires are common only where there is desecration of the Shabbat" (Shabbat 119b).
3) "Jerusalem was destroyed only because the Shabbat was desecrated" therein (ibid.).
4) When Rabbi Shimon ben Yochai would see his mother talking too much on Shabbat, he would say to her, "Mother, today is Shabbat (Yerushalmi Shabbat 15:3)."
IDOLATRY AND DESECRATION OF SHABBAT HAVE THE SAME GRAVITY
5) "We may accept sacrifices from Jewish sinners so that they will repent, except from an apostate who offers wine as a libation to idols, or a flagrant violator of the Shabbat. From here we deduce that idolatry and desecration of the Shabbat are of equal gravity" (Eruvin 69b).
6) "I would think that honoring one's father and mother would supersede the Shabbat. Scripture states, therefore: Each man shall fear his mother and father, and you shall observe my Shabbatot" (Yevamoth 5b).
7) "One who casts excessive fear upon the members of his household, will eventually desecrate the Shabbat" (Gittin 6b).
8) "Said Haman, "if you wish to uproot them, uproot the Shabbat and curtail it, afterwards you will destroy them" (Esther Rabbah 7).
9) "Tur Shimon was destroyed because they would play ball on Shabbat" (Eichah Rabbah 2:3).
10) "Desecration of Shabbat is one of three sins for which their perpetrators are blamed for committing all sins." (Midrash Tannaim, Deut. 5).
11) "Whoever desecrates Shabbat, although he possesses Torah and good deeds, has no share in the World to Come" (Avoth d'Rabbi Nathan, ch. 26).
IT IS CONSIDERED AS VIOLATING ALL OF THE TORAH
12) "If you desecrated the Shabbat, I (G-d) consider it as though you desecrated all the commandments" (Shemoth Rabbah 25)
13) "Whoever desecrates the Shabbat, testifies before He Who spoke and the world came into existence, that He did not create His world in six days and rest on the seventh" (Mechilta Yitro)
14) "Any Jew who did not observe Shabbat in this world, has no rest to eternity. One official takes his body and brings it into Gehinnom in the presence of the wicked, where his soul has no rest in the fires of Hell. When Shabbat is over, that official returns his body to its place, and each is tortured individually" (Midrash quoted by Maavar Yabbok, Sifthei Renanoth 39).
THE EXILE CAME THROUGH THE DESECRATION OF SIN
15) "Because of desecration of Shabbat, we were scattered through the Diaspora" (Tana d'vei Eliyahu Rabba ch. 26).
16) "As long as one honors his father and mother, neither the sin of desecration of Shabbat nor other sins will come about through him." (Tana d'vei Eliyahu Rabba 26).
A BEATIFUL AND AWESOME STORY
17) "This incident occurred to a man who had an ox that he used to plow with every week day. When Shabbat arrived, he would let it rest. After a time, this righteous man lost his property and was required to sell the ox to a gentile. When Shabbat arrived, the ox refused to plow, as was its wont, even after receiving many cruel blows from the gentile. Consequently, the gentile turned to the Jew, the former owner, and requested that he take back the ox. The tzaddik immediately understood, and whispered into the ox's ear that now he belonged to a gentile and was obligated to perform his master's work even on Shabbat. He immediately stood up, ready to perform his work. Upon viewing this incident, the gentile feared that the ox was enchanted and did not let the tzaddik go until he related to him the entire matter.
A SMART DEDUCTION MADE BY THE GENTILE
When the gentile heard the story, he became frightened, quaked, and deduced the following concerning himself. He reasoned, "if this animal, which has neither knowledge nor understanding, recognizes its Maker, is it not proper that I, whom the Holy One, Blessed be He, created in His image and His likeness, and gave me knowledge and understanding. Is it not proper that I, too, recognize my Maker?" Immediately, he turned to the fear of heaven and was privileged to learn Torah. He was called Rabbi Yohanan ben Torasa" (lit. the son of a cow) (Pesikta d'Rav Kahana, ch. 24; Midrash Aseres Hadibros).
18) "Because Rabbi Eleazar ben Azariah did not protest the desecration of Shabbat perpetrated through his neighbor's cow, it was counted on his name [he was held responsible] and his teeth became black on account of the fasts [he performed to repent]" (Shabbat 54 Betzah 23 Yerushalmi ibid.).
19) "Whoever desecrates Shabbat, has no forgiveness to eternity" (Midrash Tannaim, Deut. 5). [author’s remark- unless he repents wholeheartedly]
20) "Whoever desecrates Shabbat is judged as having committed all evil" (ibid.).
A SPECIAL PLACE IN GEHINOMM FOR THOSE WHO VIOLATE THE SHABBAT
21) "There is a special place in Gehinnom for desecrators of Shabbat (Zohar introd 14).
22) "Whoever desecrates Shabbat intentionally, cannot raise his head until he repents" (Letters of Rabbi Akiva).
SHABBAT IS THE NAME OF THE HOLY ONE BLESSED BE HE
23) "Shabbat is the Name of the Holy One, Blessed be He, as is explained in the holy Zohar, Shemoth 88. It is, therefore, prohibited to pronounce 'it' where we may not utter holy words of Torah, I know some very pious people who exercise caution not to mention the word Shabbat unnecessarily" (B'nei Yissochor, 1:1). 26) "It is stated in the book Ruach Chaim (by Rabbi Chaim Palaggi o.b.m.) ch. 84, that, according to Chesed L'Avraham, who maintains that, according to the Zohar, Shabbat may not be mentioned in an unclean place, one should rather say, "Shabbah" instead of "Shabbat". Without a vow, I will take care to say, "Shabbah" instead of "Shabbat" (Sedey Chemed).
WOMEN DIE DURING CHILDBIRTH FOR NOT LIGHTING SHABBAT CANDLES
24) "Because of three sins, women die during childbirth: ... One of these are because they are not careful with the kindling of the Shabbat lights" (Shabbat 31b).
25) "Both Shabbat [observance] and [the interdiction of] idolatry, are each as important to us as all the mitzvot of the Torah. Shabbat is the sign between the Holy One, Blessed be He, forever, and us. Therefore, all those who transgress other mitzvot, are included among the wicked of Israel, but those who flagrantly desecrate Shabbat are regarded as idolaters in all respects" (Rambam hil. Shabbat 7:15).
26) "An apostate for one sin is not regarded as an apostate for the entire Torah, and his slaughtering is not invalid, but an apostate who desecrates Shabbat is regarded as an apostate on the entire Torah, and his slaughtering is invalid, his wine is considered like that offered in libation to idols" (Chulin 5a, Orach Chaim 385:3 Yoreh Deah 3, 119).
QUOTATIONS FROM THE HOLY ZOHAR
1) "If one ignites fire on Shabbat, the Holy One, Blessed be He, says, "I quenched the fire so that it would not burn, yet you ignite it. You will, therefore, burn in Gehinnom" (Tikkunei Zohar 24, 69b).
2) "If the Jews do not observe the Shabbat, Scripture says: 'Sending away, you shall send away,' implying two expulsions" (Tikkunei Zohar 6, 21b).
THE ONE WHO KEEPS SHABBAT IS MADE IN G-D’S IMAGE OTHERWISE NOT
3) "If one keeps the mitzvah of Shabbat, he is "in our image." Otherwise, he has no part of the seed of Israel" (ibid. 47, 83b).
4) "All those who flagrantly desecrate the Shabbat and festivals, with no consideration for the honor of their Creator, just as they did not keep Shabbat in this world, so they do not keep it in the future world and they have no peace in Gehinnom. Rabbi Yehudah says: They keep Shabbat against their will." (Vol. 2, 150b).
THE FIRE OF GEHINOMM NEVER DIES FOR THE WICKED WHO VIOLATED THE SHABBAT
5) "Those wicked who never keep Shabbat - the fire of Gehinnom never subsides for them, and all the wicked in Gehinnom ask about them. The angels of justice reply to them: "These are the wicked who denied the existence of the Most Holy, Blessed be He, and desecrated the entire Torah by not keeping Shabbat" All the wicked emerge from their place to look at them, as one angel puts the bodies of the Shabbat desecrators into Gehinnom within view of the other wicked who see that their worms do not die, nor does their fire extinguish itself all the wicked surround him and announce, "This is so-and-so, the wicked, who had no consideration for the honor of his Creator. He denied the existence of the Holy One, Blessed be He, and the entire Torah. Woe is to him! It would have been better for him had he not been created. If so, he would not come to this judgment and action" (Vol. 2, 151).
6) Just as a person welcomes his "Neshamah Yeseirah", (his extra soul) on the eve of the Shabbat with eagerness and pleasure and joy, so will his soul be welcome upon his departure from this world" (Tikkunei Zohar 6, 23b).
7) "Shabbat is, respected more than all other festivals" (vol. 2. 88).
8) "A spirit, known as nega, a lesion, has jurisdiction over all tables that were not set on Shabbat with proper delicacies (oneg) " (vol. 2, 261b).
9) "One who can afford to delight (oneg) on Shabbat, yet does not do so, the (oneg) (pleasure) is converted for him into a lesion (nega) of leprosy" (Tikkunei Zohar 21, 58, vol 3, 273).
AMALEK ATTACKED BECAUSE ISRAEL DID NOT OBSERVE SHABBAT PROPERLY
10) "Amalek attacked Israel just because they did not keep Shabbat" (Zohar Chadash Beshallach 37b).
11) "One who detracts from the delight of Shabbat is regarded as though he steals from the Shechinah" (Tikkunei Zohar 201, 59b).
12). "One who carries out of a private domain to a public domain on Shabbat, causes the Shechinah to be void and empty, and darkness to hover over the tehom" (Tikk Zohar 30, 73b).
13) "Whoever desecrates Shabbat is left unguarded by the Holy One, Blessed be He" (Tikkunei Zohar, Introduction 12a).
14) "One who tells untruths on Shabbat, is as though he lies about the entire Torah" (vol, 2, 90a).
WE NEED TO ADD SOME TIME TO THE SHABBAT
15). "Those who do not add [minimum time] to Shabbat and festivals; if he is a scholar, his wisdom departs; if he is wealthy, his wealth departs and he becomes deprived of blessings" (Tikkunei Zohar 19, 38a).
WOE TO THE ONE WHO DOES NOT EAT THE THREE MEALS OF SHABBAT
16) "Woe to the person who does not observe the adequate number (3) of Shabbat meals" (vol. 2, 88b).
17) "One who detracts from the Shabbat meals, his punishment will be severe" (vol. 2, 88a).
18) "The one who omits a meal on Shabbat - his fault appears on high, and he demonstrates that he is not [one] of the inhabitants in the King's palace and not of the holy seed. He is sentenced to three severe punishments of the punishments of Gehinnom..." (vol. 288b).
19) "Upon the departure of Shabbat the evil forces come out hurriedly and glide throughout the world, striving to rule over the nation of Israel. The Rabbis therefore, instituted the recitation of the song of demons (Ps. 91, which refers to G- d's protection of the righteous from demons). When they see the Jews praying and reciting this Psalm, reciting havdalah in prayer and over a cup of wine, they fly away from them and on into the desert" (vol. 1, 14b).
20) "When Jews recite "ve'hee no'am" at the conclusion of Shabbat, all the wicked in Gehinnom say, "You are fortunate, 0 Israel" (vol. 2, 207a).
HONOR GIVEN TO SHABBAT AND THE GREAT REWARD OF SHABBAT OBSERVERS
(From Talmud, Midrash, Zohar, and Halachic authorities)
1)"Whoever fulfills the mitzvah of eating three meals on Shabbat, is saved from three evils; viz. the birth pangs of the Meshiach, the retribution of Gehinnom, and the war of Gog and Magog" (Shabbat 118a).
HERITAGE WITHOUT LIMITS
2) "Whoever takes delight in Shabbat is given a heritage without limits" (ibid.).
3.) "Whoever takes delight in Shabbat will be granted all his heart's desires" (Shabbat 118b).
ONE IS FORGIVEN EVEN FOR THE SIN OF IDOLATRY
4) "Whoever observes Shabbat according to the law, should he even worship idols like the generation of Enosh, he is forgiven" (ibid.).
5) "Had the Israelites observed the first Shabbat, no nation or tongue would dominate them" (ibid.).
6) "If Israel would only observe (2) two Shabbatot according to the law, they would be immediately redeemed"(ibid.).
7). "The L-rd's blessing will bring riches" (Prov. 10:22 - "This is the blessing of Shabbat" (Yerushalimi Berachoth 2:8).
8) "He who lends to Shabbat, the Shabbat repays him" (Shabbat 119a).
9) "The Holy One, blessed be He, grants the requests of those who delight in the Shabbat. (Tikkunei Zohar, 5o, 18, 33b).
10) "Whoever prays on Shabbat eve and says “Vayechulu", two ministering angels escort him, lay their on his head and say to him, "Your iniquities will be forgiven (Shabbat 119b).
11) "On the eve of Shabbat two ministering angels escort a man from the synagogue to his home. One good and the other bad, and upon his homecoming, finds a candle lit, a table and a couch covered with a spread, the good angel announces "May it be His will that next Shabbat be adorned this one," and the evil angel unwillingly responds, "Amen, (Ibid)
THE HIGHEST PRAISE BEFORE THE HOLY ONE BLESSED BE HE
12) "There is no other praise and exaltation before the Holy One blessed be He, compared to the praise of Shabbat; the Heavenly and earthly creatures all praise Him in unison, and even the Shabbat day itself actually praise Him" (Zohar Chadash Bereishit 22a).
13) "Whoever prays on the eve of Shabbat and says, 'yechullu," is considered by the Scripture as if he were a with the Holy One, blessed be He, in the work of creation (ibid.).
14) "Said the Holy One, Blessed be He to Israel, "My children, borrow on My account [buy wine in order to] recite the kiddush for the day, and believe Me that I will reimburse you" (Betzah 15b).
15) "All one's food is allotted to him from Rosh Hashanah to Yom Kippur except for the expenditures of the Shabbat" (Betzah 116a).
16) "The Holy One, blessed be He, gives a person an additional soul on the eve of Shabbat and takes it back at the conclusion of the Shabbat" (ibid.).
17) "All worlds become permeated with blessings on Shabbat" (vol. 3 94b).
EVEN THE WICKED IN GEHINOMM REST ON SHABBAT
18) When the wicked in Gehinnom are crowned on the Shabbat day, and are granted rest and tranquility" (Zohar Chadash . Bereishit 22a).
19) "On Shabbat, neither the Gehinnom nor its officials have dominion" (Tikkunei Zohar 24:69 Zohar vol. 2, 88b, 130a).
20) "The wicked in Gehinnom rest on the holy Shabbat day" (vol. 3, 94b).
21) "One who engages in mundane conversation on Shabbat, desecrates the Shabbat" (vol. 63b, Tikkunei Zohar 48, 88b).
22) "On Shabbat, no judgment is executed either above or below" (vol. 3, 288b).
23) "Just as a person makes a dwelling in his heart for the Holy One, blessed be He, and for His Shechinah, so that they are able to rest with him on Shabbatot, so does the Holy One, blessed be He prepare a dwelling for him in the World to come" (Zohar Chadash, tikkun 137).
24) "Shabbat is a bride, who is never brought in to any dwelling except one fit for her honor" (Zohar Chadash Ruth 23b).
25) "Those who run to hear the sermon on Shabbat have a special palace reserved for them" (vol. 3, 229b).
SHABBAT BRINGS ABUNDANCE FOR THE WHOLE WEEK
26) "All days of the week receive abundance in the merit of the Shabbat (vol. I 75b,).
27) "When one observes and honors Shabbat, and delights it in honor of the Holy One, blessed be He, the Holy One, Blessed be He, gives him a place on high, and he rests from the toil of this world" (Tikkunei Zohar 70, 131a).
28) "Just as a person brings pleasure to the Holy One, blessed be He, and his Shechinah on Shabbat, so does the Holy One, blessed be He, will do for him and his mate in the world to come" (Zohar Chadash, Tikkunim 137b).
29) "When the evil forces see that Jews have made a change in honor of Shabbat in all matters, both in attire and in food, they have no permission to come close to them" (Tikkunei Zohar 201, 57).
30) "On Shabbatot and festivals, Satan has no dominion; nor does he have power in Gehinnom" (vol. 3, 243).
31) "When the Holy One, blessed be He, created the world, it was unable to exist until peace and rest abided; that was the Shabbat (vol. 3, 176).
32) "Shabbat is a fortaste of the World to come" (vol. 1, 48, Zohar Chadash Bereishis 21b)