Genesis 10:21

Of Heber. That is, of the nations beyond the Euphrates. Hebrews, &c. (Calmet) --- The elder brother, fratre Japheth majore, may be rendered as well "Japheth being his elder brother," which, as we have already observed, was probably the case. By mentioning him alone, we may gather that Sem was elder than Cham, who is called the less or younger son. (Haydock) --- The Hebrew may be translated either way. But the Chaldean, Liranus, and many excellent interpreters, make Jepheth the eldest. (Calmet)