וַֽיְהִי־נֹ֕חַ בֶּן־חֲמֵ֥שׁ מֵא֖וֹת שָׁנָ֑ה וַיּ֣וֹלֶד נֹ֔חַ אֶת־שֵׁ֖ם אֶת־חָ֥ם וְאֶת־יָֽפֶת׃
Noé, étant âgé de cinq cents ans, engendra Sem, puis Cham et Japhet.
Ramban
AND UNTO THEM WERE SONS BORN AFTER THE FLOOD. The intent thereof is to imply that even though they were fit to have children before the flood — for in those generations it was normal to beget children at about sixty years of age259See above, 5:15, 21. — these did not beget children even at the age of a hundred, only until after the flood, for G-d restrained them from having children in order that they should not perish in the flood or that it [not] be necessary to save many persons in the ark. And so also did G-d do to this entire family: Lamech was delayed in begetting Noah until more than twice the age of his ancestors,260Enoch begot Methuselah at the age of sixty-five (above, 5:21), and Lamech begot Noah at the age of 182 (ibid., Verse 28). Noah begot his sons when he was five hundred years old (ibid., Verse 32). and Noah much more. This is already mentioned in the commentary of Rashi261Above, 5:32. who quotes from Bereshith Rabbah.26226:2.
Rashbam
אלה תולדות יעקב, “the following describes events and problems which Yaakov encountered in his life.” [by the way, Seforno, who lived hundreds of years later than Rash’bam, also accepts the interpretation described as nonsensical by Rash’bam. Ed.] This exegesis is nonsense. Whenever the expression תולדות occurs in the Bible, sometimes this word introduces the names of the grandsons of the party referred to, such as in Genesis 6,9 where the Torah after describing the righteousness of Noach tells us that Noach had three sons and proceeds to give us their names. The names of the sons could not be the purpose of the story there, as we had been told earlier in 5,32 that Noach at the age of 500 sired three sons and we were already told their names. The Torah then continues to describe mankind’s ongoing corruption and that Noach was the only one with whom G’d was pleased. When the Torah commences a second time with the line אלה תולדות נח in 6,9, clearly the Torah does not mean to repeat itself, but it leads to the Torah telling us of Noach’s grandchildren, something that is reported in greater detail in 10,1 under the heading of “and these are the generations of the sons of Noach.” [Perhaps the reason for the repetition of אלה תולדות בני נח in chapter 10, is that if, as the author says, the grandchildren were meant already in chapter 6, now after the deluge, the task of these children to generate a new mankind began in earnest, whereas up to that point they were charged with merely surviving the deluge. Ed.] Just as the Torah reported the growth and development of mankind after the deluge until we have a total of 70 such descendants of Noach being named, so in chapter 36,6 we have been told of the descendants of Esau who have been born in the land of Canaan, i.e. the land in which his father lived. After that, the Torah reported Esau’s further development in Mount Seir, commencing with verse 9 of that chapter. The Torah reports the development of Yaakov’s family in a parallel manner, 35,23 extending through verses 26-27 and listing all his children who had been born in exile, while he was in Padan Aram with Lavan. Now the Torah continues with the words אלה תולדות יעקב, concentrating forthwith on the grandchildren who combine to make up a total of 70 prior to the descent of the family to Egypt. Details of the birth of these various grandchildren are being provided, beginning with the chronicle of what happened to Joseph, who at 17 years of age experienced traumatic events, as a result of which his older brother Yehudah separated from the other brothers and started his own family in Keziv and Adulam, siring three sons, and grandsons respectively, i.e. Shelah, Peretz and Zerach. The history of Yaakov’s family became complicated further with Joseph having been brought to Egypt as a slave where Menashe and Ephrayim were born for him. Having attained high office, Joseph invited his father and family to join him in Egypt so that ultimately 70 members of Yaakov’s family wound up in Egypt. Moses had to record all this in order to substantiate his claim in Deuteronomy 10,22 that “your fathers descended to Egypt when they numbered only 70 persons.”
Rashi
'ויאמר אדני אם נא וגו AND HE SAID, MY LORD, IF NOW etc. — He addressed himself to the Chief of them; calling them all “lords”, (אדני may mean “my lords”), whilst to their Chief he said “Do not I pray thee pass away”, for he knew that if he would not pass by, his companions would certainly remain with him. In this explanation the word אדני has a “profane” sense (does not refer to God, being merely a term of address, “Sirs”) . Another explanation is that the word is “holy” (referring to God): he asked God to wait for him whilst he ran and invited the travellers. For although this is written after the words “and he ran to meet them”, yet the conversation took place beforehand. It, indeed, is the way of the Scriptures to speak in this manner as I have explained in my comment on “My spirit shall not strive” (Genesis 6:3) which is written after the passage. “And Noah begot” (Genesis 5:32) whereas it is impossible to say otherwise than that the decree of a respite of 120 years made in reference to this verse “My spirit shall not strive etc.” was twenty years before the birth of Noah’s sons.) Both these explanations of אדני are to be found in Genesis Rabbah 48:10 (see also Shevuot 35b).