The Talmudic tradition that there are seventy language families in the world is based on the list of Noah's descendants. This tradition of seventy(-two) meta-nations is deep-rooted. According to the Midrash each of the seventy nations is placed under the protection of a special angel, except Israel, whose Protector is G-d Himself.
The seventy bullocks sacrificed on Tabernacles were offered to atone for the seventy nations. 'Woe to the nations!' says Rav Yochanan; 'for they suffered a loss [by having destroyed the Temple] and do not realize the extent of the loss. While the Temple existed the altar [the sacrifices] atoned for them, but now [that it is destroyed] who will atone for them?'
According to many commentators this concept seems to underlie Deut. 32:8 which says that G-d 'established the boundaries of nations [i.e. the seventy nations]... according to the number of the children of Israel' -- namely the seventy who descended to Egypt with Yakov 
The seventy members of the Sanhedrin also corresponded to the seventy nations of the world. The Jewish law required that every member of the Sanhedrin should have sufficient knowledge of the seventy languages to be able to listen to testimony without an interpreter.
There was a discussion between R. Eleazar and R. Johanan with regard to the languages spoken before the Dispersion. According to the former, each nation had its own language, though it understood all the others; while the latter held that only Hebrew was spoken.
An interesting appreciation of the qualities of various languages is that given by Jonathan of Bet Gubrin. "There are," he says, "four fine languages that ought to be used by the whole world: Greek for poetry; Latin for war; Aramaic for the dirge; and Hebrew for general speech." Some add that the characters of the Assyrian language should be borrowed, but not the language itself, which is not an original one. According to a haggadah, the angels understand all languages except the Aramaic, and therefore it is recommended not to pray in that language. Gabriel, however, is an exception to the rule, for to his teaching the haggadah attributes Joseph's knowledge of all the seventy languages. "The astrologers," it is related in the haggadah, "said to Pharaoh: 'What! Shall a slave who was bought for twenty pieces of silver rule over us?' Pharaoh replied: 'But I find him endowed with kingly attributes!' 'If that is the case,' they answered, 'he must know the seventy languages.' Then Gabriel taught him all the seventy languages"
The Torah was written in seventy languages in order that the nations should not be able to plead ignorance as their excuse for rejecting it. Among the seventy languages the most noble is Hebrew, for in it was pronounced the creative word of G-d.
Just as there were seventy nations, the words of the Torah engraved on the Tablets on Mount Ebal were written in seventy languages so that all the nations might read it. For the same reason, G-d's voice at Sinai divided itself into seventy languages.
Parallels to the Seventy Nations
Harav David Feinstein explains the significance of the many parallels to the seventy nations: the seventy languages into which the Torah was translated, the seventy offerings of Tabernacles, the seventy members of the Sanhedrin.
Indeed, on the verse "He established the boundaries of nations according to the number of the children of Israel", the Sages comment that G-d established seventy nations because Jacob's family numbered seventy when he descended to Egypt. Why was it necessary for the number of nations to correspond to the number of Jews? Moreover, at the conclusion of the forty years in the desert Moses explained th Torah to the Jews in all seventy languages. Why was necessary for him to use seventy languages when all his listeners were Hebrew-speaking Jews?
Each of the seventy nations represented a unique characteristic, as the Sages say, one excelled in warfare, another in licentiousness, another in beauty and so on. All of these national virtues and strains of character are present in Israel as well for each person has gifts to develop and temptations to overcome. G-d wants all nations to rise to their greatest spiritual potential.
These variations were present in the individuals of Jacob's family. And the seventy languages used by Moses parallel the seventy facets of Torah; each 'speaks' to one of the seventy characteristics with which G-d has populated the world. (It may also be suggested that each of the seventy offerings of Tabernacles atoned for the trespasses of each of these seventy national characteristics present within Israel, and consequently the nations of the world benefited from this universal atonement).
Israel, as the spiritual model of the world, was to demonstrate within itself that eminence is within reach of every nation; that every type of person can live a Torah life.
Therefore, a significant portion of Jewish life revolves around the number seventy to symbolize that every national trait can become harnessed for holy purposes.
Table of Nations
The majority of Palestinian and Babylonian scholars considered the ethnological table to be a simple historical narrative, enumerating, without any pretense to completeness, the descendants of Noah, and indicating the places they had chosen for their respective residences. This is clearly expressed by R. Huna of Sepphoris, who, interpreting Canticles 6:8 as an allusion to the nations and their languages, says: "Sixty and eighty are one hundred and forty. Of these, there are seventy nations, each of which possesses a separate language but not a separate script, and seventy other nations, each of which possesses both a separate language and a separate script; as to the nations which possess neither a separate language nor a separate script, they are numberless" (Cant. R. l.c.). In a later midrash, the "Midrash ha-Gadol," it is inferred from Cant. vi. 8 that there were only sixty original nations, eliminating from the ethnological table the ten nations descended from Japheth, Gomer, Javan, Ham, Cush, Raamah, Shem, Mizraim, Aram, and Joktan. As to the languages, the "Midrash ha-Gadol" counts seventy-two, as do the Christian authorities. "The total number of the countries that the children of Noah divided among their descendants was 104; of islands, 99; of languages, 72; and of scripts, 16. To the share of Japheth fell 44 countries, 33 islands, 22 languages, and 5 scripts; Ham received 34 countries, 33 islands, 24 languages, and 5 scripts; Shem, 26 countries, 33 islands, 26 languages, and 6 scripts."
The haggadic assumption that there are seventy nations and languages in the world is based upon the ethnological table given in Genesis 10, where seventy grandsons of Noah are enumerated, each of whom became the ancestor of a nation. The earlier Christian writers also took this table as determining the number of existing nations and languages; but reckoning with the Septuagint, which counts seventy-two grandsons of Noah, there must be seventy-two nations and languages (see Augustine, "De Civitate Dei"; Anio, in his commentary on the second book of Berosus; comp. Azariah dei Rossi, "Me'or 'Enayim, Imre Binah," xlviii.). The Haggadah seems to have followed in this case the theory of the Hellenists, who regarded the ethnological table as a scientific and complete division of mankind into three races, distributed among three separate zones. This theory is expounded in the Book of Jubilees; "and at the beginning of the thirty-third jubilee they divided the earth into three parts between Shem, Ham, and Japheth, according to their inheritance" (ch. viii.).
Enumerating the Nations
There is some disagreement as to how the count of seventy nations is to be derived from the following verses. A counting of the names -- including Shem, Cham and Yafet, will reveal a total of seventy-four.
The common system (following Pesikta Zutresa; Torah Sheleimah 9:110) of ascribing 14 nations to Yafet; 30 to Cham; and 26 to Shem, totaling seventy. Shem, Cham and Yafet themselves are omitted as are the Philistines who, according to Genesis 10:14 are designated as a mixed race.
Others include the Philistines but omit Nimrod from whom a separate nation did not descend.
Yalkut Shimoni attributes 15 nations to Yafet, 32 to Cham, and 27 to Shem, totaling 74. However, Shem, Arpachshad, Shelach and Ever were too righteous to be counted among the general, leaving the total again at 70.
Attempts were made by the Rabbis to identify those nations which were not known to the average reader. The Targumim to Genesis 10 and I Chron. i., both the Palestinian and the Babylonian Talmuds, and various midrashim, interpret many of the names of the Biblical nations in the light of their geographical and ethnological knowledge. The links below list the rabbinical identifications according to Samuel Krauss, the second column giving the countries or places with which the various "nations" are associated.
The sons of Shem were not identified by the Rabbis because they were known, and of the Canaanite nations only the following places are given: Arthasia (city in Phenicia); Gebalene (in Idumea); Acra (in the Lebanon); Aradno (in Phenicia); Emesa (in Syria); Epiphania (in Syria); Callirhoe (to the east of the Dead Sea); Sidon; Tripoli (Phenicia); Cyprus.
- R' Bachya
- Genesis Rabbah 37
- Sukkah 55b, Pesikk. 193b, 195b
- Radak, Ralbag, Chizkuni, Malbim
- Genesis 46:27
- Targum Yerushalmi to Genesis 28:3
- Sanhedrin 17a; comp. Megilah 73b; Menachos 65a
- Genesis Rabbah 11:1
- Yerushalmi Meggilah 1,71a
- Shabbos 12b
- Sotah 36b; Yalkut Re'uveni, Miketz, 71b
- Tosef., Sotah 8
- Genesis Rabbah 18, 31; Yalkut, Genesis 52
- cf. Targum Yonasan to 11:7
- Deut. 27:2ff
- Mishna, Sotah 7:5
- Shabbos 58b; Shabbos 88a; Exodus Rabbah 5; comp. Acts ii. 5
- Deut 32:8
- Deut. 1:5 see Rashi
- Artscroll Bereshis, Vol 1, p. 309
- Yalkut Shimoni 61