I'm having a bit of trouble understanding Or Hachaim's explanation on Breishit 29:18. Usually Jewish slaves work for only 6 years. Yet, Ya'akov offers to work for Lavan for 7 years as payment for marrying Rachel. Ohr Hachaim says that there is a "secret" behind the number 7. Despite that, esp. if Ya'akov had already suspected that Lavan was not trustworthy, why did he offer his work for so many years? (I may be missing something in Ohr Hachaim's explanation that would answer this.)
“…and the (seven years) seemed to him only a few days, because of the love he had for her.” Genesis 29:20
Abraham Joshua Heschel wrote:
Should not the reverse be true, i.e. that a day should seem to Jacob like years because of his love for Rachel?
The wording of this passage is meant to convey to us the profound spiritual nature of the love that bound Jacob and Rachel to one another. In a love based on physical desire, the lovers want the time of separation to pass quickly so that each day they are apart seems to them like a year.
But in a spiritual love, devoid of self-seeking desire, such as that of Jacob and Rachel, the lovers do not care whether the object of their affection is near or far away. The spiritual love between Jacob and Rachel had already found fulfillment, and therefore, seven years seemed to Jacob only a few days.
Before we go into the main topic i.e
why Ya'akov enslaved himself for so long?
We need to understand more about his father-in-law "LABAN"
Laban is identified by the Rabbis with Beor, Balaam's father, and with Chushan-rishathaim (Judges iii. 8), the last name being interpreted as "perpetrator of two evils" (Sanh. 105a; comp. Targ. pseudo-Jonathan to Num. xxii. 5).
R. Joshua b. Levi, however, identifies Laban with Kemuel (Gen. xxii. 21), the latter name being interpreted as, "who stood up against God's people"
Laban is called also "the master of impostors" (ib. lxxv. 6). When he saw the bracelets on Rebekah's arms (Gen. xxiv. 30) he determined to kill Eliezer; but the latter, divining his intention, pronounced the Sacred Name, by which he caused camels to remain suspended in the air above the well. This and Eliezer's resemblance to Abraham made Laban believe that Eliezer was Abraham. Laban therefore invited him to enter the house (Midr. Abkir, in Yalḳ., Gen. 109; comp. Midr. Hagadah on Gen. xxiv. 23).
When Jacob had completed his seven years of service, Laban assembled his countrymen and consulted them as to the best means to retain him; "for," said he, "ye know that formerly we had a scarcity of water, and it is only through this righteous man that we are now blessed with an abundance of it." His countrymen advised him to substitute Leah for Rachel (Targ. pseudo-Jonathan and Yerushalmi to Gen. xxix. 22; Gen. R. lxx. 17).
First, is your question about 7 years as opposed to 6 or in general, why so many years? Because I asked something similar - why not use his father's wealth to get away from the work altogether and nobody responded yet.
I don't know a clear answer, but I can only hint you, based on Baash"t and Ariz"l explanations on Yaakov's mission at Lavan. If you remember, he stole Eisov's Brochos, and therefore, Eisov's mission in this world. His original mission was a Torah learner (Aseh Tov) but now he needed to be Ish Tzayd, to complete Eisov's mission of Sur meRah. This is the reason he went away to Lavan to Huzt laHaretz, the land of idolatry, instead of his father's bringing Rochel home to the Holy Land.
This is the reason he spent those long years at Lavan's residence Mamash as Lavan insisted, constantly fighting Lavan (Sur meRah) and going through all those tests and humiliations etc, instead of grabbing the grown-up daughters and running away back home.
I am sorry I'm really bad with sources, I simply don't remember who said that, and don't have time to search it up (source needed) but Eisov was one to father and establish the 12 Tribes, but now Yaakov took it all. Isn't it strange he realized he should have children at 84?
So the answer (according to Drush) is that that was his new mission he took from Eisov to cope with Lavan's evil 3 times 7 years, you probably know what those numbers stand for.
Sorry again for not bringing sources.