And Noah began to be an husbandman, and he planted a vineyard: 21And he drank of the wine, and was drunken; and he was uncovered within his tent. 22And Ham, the father of Canaan, saw the nakedness of his father, and told his two brethren without. 23And Shem and Japheth took a garment, and laid it upon both their shoulders, and went backward, and covered the nakedness of their father; and their faces were backward, and they saw not their father's nakedness. 24¶And Noah awoke from his wine, and knew what his younger son had done unto him. 25And he said, Cursed be Canaan; a servant of servants shall he be unto his brethren. 26And he said, Blessed be the LORD God of Shem; and Canaan shall be his servant. 27God shall enlarge Japheth, and he shall dwell in the tents of Shem; and Canaan shall be his servant. — Genesis 9:20-27
Some commentators have said that the "youngest son" is Canaan, based on the fact that Ham was not Noah's youngest son, and that the word "son" also means "grandson" in Hebrew, along with the fact that Canaan was punished, and not Ham. What is most probable based on the text?