Bamidbar 26:23-25 במדבר כ״ו:כ״ג-כ״ה

לישוב. הוּא יוֹב הָאָמוּר בְּיוֹרְדֵי מִצְרַיִם, כִּי כָל הַמִּשְׁפָּחוֹת נִקְרְאוּ עַל שֵׁם יוֹרְדֵי מִצְרַיִם, וְהַנּוֹלָדִין מִשָּׁם וָהָלְאָה לֹא נִקְרְאוּ הַמִּשְׁפָּחוֹת עַל שְׁמָם, חוּץ מִמִּשְׁפְּחוֹת אֶפְרַיִם וּמְנַשֶּׁה שֶׁנּוֹלְדוּ כֻלָּם בְּמִצְרַיִם, וְאַרְדְּ וְנַעֲמָן בְּנֵי בֶלַע בֶּן בִּנְיָמִין; וּמָצָאתִי בִיסוֹדוֹ שֶׁל רַבִּי מֹשֶׁה הַדַּרְשָׁן, שֶׁיָּרְדָה אִמָּן מִמִּצְרַיִם כְּשֶׁהָיְתָה מְעֻבֶּרֶת מֵהֶם, לְכָךְ נֶחְלְקוּ לְמִשְׁפָּחוֹת כְּחֶצְרוֹן וְחָמוּל שֶׁהָיוּ בְנֵי בָנִים לִיהוּדָה, וְחֶבֶר וּמַלְכִּיאֵל שֶׁהָיוּ בְנֵי בָנִים שֶׁל אָשֵׁר; וְאִם אַגָּדָה הִיא הֲרֵי טוֹב, וְאִם לָאו, אוֹמֵר אֲנִי שֶׁהָיוּ לְבֶלַע בְּנֵי בָנִים הַרְבֵּה, וּמִשְּׁנַיִם הַלָּלוּ, אַרְדְּ וְנַעֲמָן, יָצְאָה מִכָּל אֶחָד מִשְׁפָּחָה רַבָּה, וְנִקְרְאוּ תוֹלְדוֹת שְׁאָר הַבָּנִים עַל שֵׁם בֶּלַע, וְתוֹלְדוֹת הַשְּׁנַיִם הַלָּלוּ נִקְרְאוּ עַל שְׁמָם, וְכֵן אֲנִי אוֹמֵר בִּבְנֵי מָכִיר שֶׁנֶּחְלְקוּ לִשְׁתֵּי מִשְׁפָּחוֹת, אַחַת נִקְרֵאת עַל שְׁמוֹ, וְאַחַת נִקְרֵאת עַל שֵׁם גִּלְעָד בְּנוֹ; חָמֵשׁ מִשְׁפָּחוֹת חָסְרוּ מִבָּנָיו שֶׁל בִּנְיָמִין, כָּאן נִתְקַיְּמָה מִקְצַת נְבוּאַת אִמּוֹ שֶׁקְּרָאַתּוּ בֶן אוֹנִי — בֶּן אֲנִינוּתִי, וּבְפִילֶגֶשׁ בְּגִבְעָה (שופטים כ') נִתְקַיְּמָה כֻּלָּה. זוֹ מָצָאתִי בִיסוֹדוֹ שֶׁל רַ' מֹשֶׁה הַדַּרְשָׁן:

From Yashuv. This is Yov, mentioned among those who went down to Egypt, as all of the families were called by the names of those who went down to Egypt. As for those who were born afterward, none of the families were called by their names, except for the families of Efrayim and Menashe, all of whom were born in Egypt, and Ard and Na’aman, the sons of Bela, the son of Binyamin. I found, in the commentary of R’ Moshe Hadarshan, that their mother went down to Egypt when she was pregnant with them, and they were, therefore, divided into separate families, like Chetzron and Chamul, who were Yehudah’s grandsons, and Chever and Malkiel, who were Asher’s grandsons. If this is from the Aggadah, fine, but if not, then I say that Bela had a great many grandchildren, and from those two, Ard and Na’aman, respectively, large families emanated. The descendants of the other children were called by Bela’s name, while the descendants of those two were called by their names. I say the same about the sons of Machir, who were divided into two families, one called by his name, and one called by the name of his son, Gil’ad. Five families are missing from the sons of Binyamin. Here, his mother’s prophecy was partially fulfilled — she called him בֶּן אוֹנִי, “son of my sorrow.” With the concubine of Givah, it was completely fulfilled. I found this in the commentary of R’ Moshe Hadarshan.