After cursing Canaan, Noah speaks of his two sons Shem and Japheth:
He also said,Notice that twice in this blessing, Noah reinforces the curse on Canaan. Notice also that between Canaan, Shem, and Japheth, Shem is the son that Noah honors the most. Noah calls Yahweh the God of Shem, but does not call Yahweh the God of Canaan or the God of Japheth.
"Blessed be the LORD,
The God of Shem;
And let Canaan be his servant.
"May God enlarge Japheth,
And let him dwell in the tents of Shem;
And let Canaan be his servant."
This distinction may seem strange at first, but if you jump forward a few chapters to Genesis 11, you will see that Shem is one of Abraham’s ancestors. Shem, then, is singled out by Noah because the Hebrew people would come from his lineage. Even more importantly, from the lineage of Shem came Jesus Christ: who saves all those who come to Him, regardless of ancestry.
After blessing Shem, Noah speaks of Japheth's future, saying, "May God enlarge Japheth". Noah then says that Japheth will "dwell in the tents of Shem". This could possibly be referring to the Romans who were descendants of Japheth and eventually conquered Judah— thus the descendants of Japheth would be dwelling in the "tents" of Shem. Another possible interpretation is that through the lineage of Shem they received the good news of the gospel, which could be considered a type of spiritual tent.