Who was Yashuv - who was not mentioned in Vayigash among those who went down to Egypt?
Rashi: "Yashuv" is synonymous with "Yov", who is mentioned there. 1
See Sifsei Chachamim. Rashi adds that basically, all the families were named after those that went down to Egypt, with the exceptions that he will discuss in the forthcoming Pesukim.
Seeing as, with the exception of B'nei Efrayim and Menasheh, only descendants of Ya'akov who were already born when they went down to Egypt were counted as separate families, why are Ard and Na'aman, sons of Bela ben Binyamin, listed here as families?
Rashi #1 (citing R. Moshe ha'Darshan) 1 : Because, although Ard and Na'aman 2 were born in Egypt, their mother was already pregnant with them when they left Cana'an. 3
Rashi #2: Bela had many children and grandchildren, all of whom were considered part of his family, with the exception of Ard and Na'aman, who had many offspring of their own, and who are therefore listed as independent families. 4
Ramban #1 (in Pasuk 13): Because Ard and Na'aman sons of Binyamin, died without children, and Bela, wanting to perpetuate his brothers' names, called his sons after them. 5
Ramban #2 (in Pasuk 13): The Ard and Na'aman listed in Vayigash were really sons of Bela, Binyanim's son, 6 as they are listed here. 7
Ramban #3 (in Pasuk 13): The families are not limited to the seventy who went down to Egypt. It was customary to divide large families into smaller family groups and to appoint a head over each segment. 8 And that explains why many of those listed here were not listed in Vayigash ? since they were born in Egypt. 9
See Ramban, DH 'va'Ani Tamah alav '.
The namesakes of their uncles (Binyamin's sons).
In which case they were twins.
Rashi: And the same applies to Menasheh's son Machir, whose son Gil'ad had many offspring of his own and who is therefore listed as an independent family.
Ramban: Perhaps even by means of Yibum ? since he was the B'chor, he performed Yibum with both their wives.
Ramban: Based on the principle 'B'nei Banim, Harei Hem ke'Banim', a principle which the Torah often employs ? See for example, Vayeitzei, 29:5 and Divrei ha'Yamim 1, 1:17). See Ramban, DH 'Aval Nuchal Lomar'.
Ramban: And in Divrei ha'Yamim 1, 8:1-5.
Ramban: Like the Yishme'eilim do today, and like we find the family of Ibn Ezra and Ibn Shushan.
Ramban: This custom probably began in Egypt ? to avoid becoming assimilated with the Egyptians (See Ramban DH 've'Ulai').
