Why because Ham had sinned did God pronounce that his son Canaan should be the servant of Ham and Japhet? (Genesis 9:27).
In the first place, God pronounced this sentence because both father and son had displayed the same wickedness, being both united together and not separated, and both indulging in the same disposition. But in the second place, he did so because the father would be exceedingly afflicted at the curse thus laid upon the son, being sufficiently conscious that he was punished not so much for his own sake as for that of his father. And so the leader and master of the two suffered the punishment of his wicked counsels, and words, and actions. This is the literal meaning of the statement. But if we look to its inward meaning, then in reality they are no more two different men than two different dispositions. And this is made plain by the names given to them, which manifestly denote the nature of the facts; for Ham being interpreted means heat or hot; and Canaan means merchants of causes.