Who knows seventy?
Please cite/link your sources, if possible. At some point in the next few days, I will:
Upvote all interesting answers.
Accept the best answer.
Go on to the next number.
Seventy defects that render an animal tereifah (Rambam, Hil. Shechita 10:9).
The chilazon that is used in the manufacture of techeiles comes up from the sea once every seventy years. (Menachos 44a)
The animal called אפעה ("vipers" - Artscroll) becomes fertile seventy years after birth, and the carob tree does not bear finished fruit until sevety years from its planting. (Bechoros 8a, acc. to Rashi)
Seventy are the "days of our years" (Tehillim 90:10), and one who reaches that age is in the category of שיבה (Mishnah, end of Avos).
The Babylonian exile lasted seventy years.
The first four spices listed in the ketores recipe (tzari, tziporen, chelbenah, levonah) each had a weight of seventy maneh.
Once every seventy years, the young Kohanim in the Temple would extract the congealed wine from the shissin into which the Nesachim (libations) were poured. (Me'ilah 11b)
Seventy are the years King David lived.
(It fits the rhythm of the song ... or did we forget all about that a long time ago?)
And the old story of the guy who said the entire book of Psalms every day, his rabbi comments, "it took King David seventy years to write Psalms, and you polish it off in two hours?" (Or something like that; please correct me on the story.)
While on the topic of the Nesiim, seventy are the shekels' weight of the silver basin each Nasi brought, a bit less than three lbs. (Plus the weight of the flour it contained; as we don't know the shape of the basin -- Kodshim experts, do we? -- we can't tell it's volume; though I suppose we could guess some reasonable shapes and calculate accordingly.)
Seventy are the bulls brought as olah-offerings on Sukkot, 13+12+11+10+9+8+7. As the Vilna Gaon famously observed, on some of the days the goat offering is called a "se'ir", and on some it's called a "se-ir izim." (The JPS translation linked just calls both of them a "he-goat.") Sure enough, there are 35 bulls brought on "se'ir" days, and 35 bulls brought on "se'ir izim" days. Question: is the division given in the Chumash the only way to get 35 + 35?
The Sforno says the bulls represent getting the big picture -- love and fear of G-d. And the diminishing means that over history, the Jews will be observing all sorts of rituals, but increasingly missing the big ideas.
Avraham was 70 when he first came to Eretz Canaan and experienced the Bris bein haBesarim. Seder Olam
The Chizkuni explains this in more detail:
During the Bris (Lech Lecha 15:7-21), Hashem says your children will be strangers...for 400 years. However, it says in Bo (12:41) that the Bnei Yisrael went out at the end of 430 years. He differentiates that, indeed, "your children" (starting from Yitzchak) will be strangers for 400 years, but it will be 430 years from the Bris bein haBesarim. Yitzchak was born when Avraham was 100, so the Bris was when he was 70. We know he was in Eretz Canaan because Hashem says He took Avram out of Ur Kasdim to give him "this land".
Another indication that pesukim 7-21 were prior to 1-6 is that the gemara (Brachos 7b) says that Avraham was the first to refer to Hashem as Adon and quotes Pasuk 8. If 1-6 came before 8, the gemara should have quoted pasuk 2 where Avram also uses adnus.
Another indication that pesukim 7-21 were prior to 1-6 is that Avram asks Hashem for a sign that he will posess the land. That's a massive short-coming of Emunah since Hashem just told him that he'll get the land. If 7-21 came first, then the request makes sense- Hashem never promised Avram children yet (that's in 1-6), just the land. Avraham is concerned that Hashem will give the land, but Avram will die without an heir. (Avram wants a sign for long-term ownership.) [#2-#3 don't indicate age, just the order]
An indication that 1-6 was said at a different time as 7-21 (but not of age or order) is that 1-6 was at night (Machaze (1) is a night vision; Count the stars ). 7-21 was in the day (the sun was setting
[Another answer to this question is how many answers there will be to this question]
According to R' Elazar ben Azaryah, a court that executes a person once in seventy years (or alternatively, more than once in seventy years) is called חבלנית, destructive. (Makkos 7a)
Rav Huna wrote 70 Sifrei Torah in his lifetime (Bava Basra 14a)
The Ramban moved to Eretz Yisrael when he was 70.
Daniel prophesied (9:24) that the second Temple would be destroyed "seventy sevens" (=490 years) after the destruction of the first.
Seventy are the answers of Rabbi Yosef Engel.
There's an apparent contradiction between R' Ashi's opinion in Pesachim and his opinion in Zevachim; if I understand correctly, in Pesachim, he holds "mishras / ta'am k'ikar medeoraysa", there's a general principle that if food A absorbs a good deal of food B, it now takes on the added halachos of food B. (E.g. if food B is non-kosher). But in Zevachim, concerning various sacrificial meats that absorb from one another, it seems that "mishras / ta'am k'ikar" is ignored, and a specialized kodshim answer is given instead. That's the question.
Rabbi Engel published a book in 1889 giving no less than seventy different ways to answer this problem!
At one point I'd heard there were 70 answers to the question of "what's the miracle of the first night of chanukah", but then they got up to 100 answers (and I think published it as "ner leme'ah").
Yosef spoke 70 languages
Moshe translated the Torah into 70 languages.
Yehoshua (or was it moshe?) wrote the Torah in 70 languages on stones in the Yarden.
The Tanakh was translated by 70 rabbis from Hebrew to Greek (The Talmud says 72 (megilla 9b), but maybe the Latin "septuagint" is just rounding down. In any case, as I have heard from my rabbi, it was no miracle that all 72 rabbis--in separate rooms--came up with the same translation. it would have been a miracle to put 72 rabbis in the SAME room and have them agree!)
The second Temple was destroyed in 70 CE (may it be rebuilt speedily in our days!)
(is it possible that I missed these above?)
Horayos 10a records the statement of R' Yehoshua that every seventy years, a star (Halley's comet?) comes up that confuses the sailors.
The nominal Tikkun count in Tikkunei HaZohar. (See item 22 here.)
From Bamidbar Rabbah 14:12, the 70 shekel silver basins (mentioned by Shalom) are keneged:
70 nations (mentioned by Chanoch)
70 Pesukim from beginning of Breishis until Curse of Nachash (Arur Atta
70 Pesukim from Haman's promotion (gidal hamelech) until his hanging (vayislu es Haman)
70 names of Hashem from Breishis until the parashah of the Nachash
70 years until Terach begat Avraham
70 years until Kenan begat Mehalalel
70 days of crying in Mitzrayim for Yaakov
70 Shabbossim/Yamim Tovim in a Solar year
70 names for Hashem
70 names for Yisrael
70 Names for the Torah
70 names for Yerushalayim
70 years given from Adam to Dovid (same as Shalom)
What is the source of this halacha, and why is it 70? Doesn't seem to be related to most of the other seventies here -- at least not at first glance.