From these: these cannot refer to all the names given in verses 2-4, because not all are coastland peoples, that is, people living along the sea coast. The reference is to the people of the islands and coasts of the Mediterranean, that is, to the descendants of Javan in Gen 10.4. Good News Translation, which translates “they were the ancestors…,” makes it clear that verse 5a refers to the names in Gen 10.4. We may also say, for example, “from Javan’s descendants…” or “The people who live along the coast and on the islands of the Mediterranean are the descendants of Javan.”
Spread translates the passive form of a verb meaning to divide or separate and is used in Gen 2.10 of the river that flowed out of Eden and divided into four streams. New English Bible translates “From these the peoples of the coasts and islands separated into their own countries.”
These are the sons of Japheth does not appear in the Hebrew text. See Revised Standard Version footnote. Both Revised Standard Version and Good News Translation supply this statement on the basis that it is part of the closing refrain used in verses 20 and 31 in regard to the descendants of Ham and Shem respectively. It is assumed that the absence of the refrain in verse 5 is an accidental omission in the text. However, not all translations supply this statement; and Hebrew Old Testament Text Project, which considers the Hebrew text to have here an {A} value, does not recommend adding These are the sons of Japheth.
Translators in some languages may wish to follow the example of a major language in the area. For other translators the natural structure of the list will require something like these words as a closing statement for each of the three main divisions, regardless of the decision textual scholars may reach.
The sons of Japheth in this closing statement must refer to Japheth’s “descendants,” as Good News Translation makes clear. In some languages there is a special term for the person known as the ancestor of a tribe or clan, which is very appropriate here. One Pacific creole language, for instance, says “All these peoples were descended from the old man Japheth.”
The closing formula in their lands, each with his own language, by their families, in their nations provides a four-way classification of these groups: geographical, linguistic, sociological, and political. In their lands refers to the land or area each group occupies. Each group is bound together with his own language. By their families refers to their social grouping, which regulates social and kinship relations. In their nations calls attention to their political boundaries.
The word translated families is used in the Old Testament to refer to the subdivisions within the people of Israel as well as to the people as a whole. Although many translators use the word “clan” in the former sense, in some languages that term may not be appropriate in this context.
The translation of families as “tribes” (see Good News Translation) may be inadvisable in some languages, as this term may be considered disrespectful. If there are terms such as “societies,” “human groups,” “ethnic groups,” or “peoples,” these may be more acceptable.
Good News Translation translates these four classifications as “… living in their different tribes and countries, each group speaking its own language.” In some languages lands and nations are difficult to distinguish. However, we may sometimes translate in their lands as “in their territories,” “in their regions,” “in their areas,” or “in their part of the world.”
Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .