Genesis 9:27

God shall enlarge Japheth, and he shall dwell in the tents of Shem; and Canaan shall be his servant.

1. Like the previous verse, this appears to be a prophecy concerning the future of Noah's posterity.
2. The posterity of Japheth will be numerous.
3. Japheth shall dwell in the tents of Shem, suggesting a close relationship of some kind between their posterity, some type of sheltering or supporting of Japheth's descendants by the descendants of Shem - that is, actual or spiritual Israel.
4. The descendants of Canaan shall be servants to the posterity of Japheth.
5. God may bless groups of people to grow numerous. In a broader sense God may exercise or neglect to exercise power or influence over factors affecting population growth.