Komentaryo sa Genesis 10:21: Rashi, Chizkuni, Ramban & Sforno

אבי כל בני עבר THE FATHER OF ALL THE CHILDREN OF EBER — (עבר means the “side” or “ other side” of a river) — The father of all the children of עבר הנהר, the other side of the River (Euphrates), was Shem.

ולשם יולד וגו, “and for Shem were born, etc.” In these verses (221) the three sons are listed in the order of their ages. As to the reference to Yephet as the הגדול, “the big one,” this adjective was used here to ensure that we realise that he was the oldest. If his other brothers were sometimes mentioned ahead of Yephet, this was only in order to underline an important act performed by the one concerned.

AND UNTO SHEM, TO HIM ALSO WERE CHILDREN BORN. Since Scripture delayed the narration of the generations of Shem and related the generations of his younger brother as if Shem had no children, it therefore says here, to him also.

אחי יפת הגדול [SHEM …] THE BROTHER OF JAPHETH, THE ELDER — (The Hebrew is ambiguous: “the elder” may refer either to Shem or to Japheth). One cannot from here determine whether Japheth was the elder or Shem. Since, however, it states (10:10) “Shem was a hundred years old … two years after the flood” you must admit that Japheth was the elder. Because Noah was 500 years old when he first had children (5:32), and the Flood happened in the six hundredth year of his life (7:11), consequently the eldest of his sons was then one hundred years old, whereas Shem reached his hundredth year only two years after the Flood (and therefore Japheth was the elder of the two) (Genesis Rabbah 37:7).