When Noah awoke from his wine and found out what his youngest son had done to him, he said,
“Cursed be Canaan!
The lowest of slaves
will he be to his brothers.”
Genesis 9:24-25 (NIV)
Why did Noah's curse in Genesis 9:25 fall on Canaan and not on Ham?
Perhaps Ham might not be able to be cursed, because he was already blessed in Genesis 9:1.
Then God blessed Noah and his sons, saying to them, “Be fruitful and increase in number and fill the earth."
Genesis 9:1 (NIV)
No curse can fall on him because the Lord had already blessed him, and Noah's curse cannot be greater than God's blessing.