Genesis 9:25

And he said, Accursed is Kenaan who is his fourth son, a serving servant shall he be to his brethren.

Kush and Mitzrayim and Put are descendents of their father. And there are those who claim that Kushim are slaves because Noah cursed Ham; yet, they have forgotten that the first king after the deluge was from Kush and thus one should say that the head of the kingdom of Babylonia was from Kush.

עבד עבדים יהיה לאחיו, his being in a position of dependence to his senior brothers, i.e. a plain עבד, was merely natural, and would not have been a special curse, especially in view of his disgraceful conduct. Solomon paraphrased this in Proverbs 11,29 when he spoke about ועבד אויל לחכם לב, that “a fool is a slave to the wise-hearted.”

ויאמר ארור כנען, he cursed Canaan by invoking his prophetic vision, so that his curse would take lasting effect. All he patriarchs were extremely careful not to marry women descended from these cursed tribes. Avraham had already warned Eliezer his servant, against taking a wife from these tribes for Yitzchok, and so had Yitzchok as well as Rivkah expressed their opposition to such liaisons.

עבד עבדים, even his brothers would be slaves too; but he, Canaan, would be a slave even to them.

ויאמר (נח) ארור כנען, “Noach said: “Canaan be cursed and become a lowly slave to his brothers" Our sages in B’reshit Rabbah 36,7 state that already when Noach entered the ark, he had been upset that he did not have a young son who could perform for him many chores that it had now become his task to perform personally. He therefore had resolved that when he would sire more children after leaving the ark, he would train some as his servants. Upon hearing him say something of that nature, his grandson Canaan went ahead and castrated him to prevent him from having more children. Noach therefore decided to treat Canaan as if he had been his fourth son and decreed that he should become a servant to his brothers. If you were to ask why he cursed Canaan more than anyone of Cham’s other children, a question which is justified according to the opinion that it had been Canaan who had castrated him, [Canaan could not have been even one year old when Noach left the ark, so that Noach must have failed to impregnate with wife until he had grown up, Ed.] how do we answer the problem according to the opinion that it was his son Cham, and not his grandson who had castrated him? A sage by the name of Rabbi Aaron, found a Midrash that Cham had discovered his father in a state of nudity, and told his brothers about it in a derogatory manner, and he had been overheard by Canaan, who had decided to castrate his grandfather. This is the meaning of the puzzling words: את אשר עשה לו בנו הקטן, “what his son the minor had done to him” (9,24) Grandchildren are often referred to in the Torah as if they were children, not grandchildren. Actually, the line could not have referred to Cham, as he was not Noach’s youngest son, as the Torah lists him as his middle son. (10,1) The Torah, in referring to Canaan as Noach’s youngest son, meant his grandson. [At that time he only had one grandson, so that he did not have to be named. Ed.] We find proof that grandsons may be called younger sons in Ovadiah: 1,2: הנה קטון נתתיך בגוים, “here I will make you the least among the nations;”Furthermore, according to Pirkey de rabbi Eliezer, chapter 23, the line in Malachi 1,6: בן יכבד אב ועבד אדוניו, “a son is expected to honour his father, and a servant his master,” is interpreted as follows: when a son honours his father, all is well; if not, he will wind up as a servant to his master. [not found in my edition of the Pirkey de Rabbi Eliezer. Ed.] An alternate interpretation. The reason why Noach chose as punishment that the person who witnessed his disgrace become a slave was that seeing he was the one who saw his state of nudity first, it was his duty to do what any servant would to, i.e. to cover his nudity. Seeing that he had neglected to perform the duty of a servant, he was now condemned to remain a servant all the time. This is also why he used the expression עבד עבדים, “a servant of servants,” instead of simply עבד “servant.” Both Cham and his son Canaan were condemned to be servants to Cham’s brothers.