שמות ו ,יד : אֵלֶה רָאשֵי בֵית־אֲבֹתָם בְנֵי רְ אוּבֵן בְכֹר יִשְרָאֵל
Rashi gives two reasons for inserting this partial genealogical table at this point breaking the flow of the narrative (until verse 27)
The Sforno, however, understands these verses as follows: HaShem appointed Moshe and Aharon as leaders, who were descendants of the Levi, the third son. Why were Reuven and Shimon denied the leadership?
The Sforno explains that although Reuven was the firstborn, only his four sons were worthy to be mentioned by name in the Torah, but none of the following generations. The same was true of Shimon. This indicates that the third and successive generations were not of the same high level of distinction as the initial generations. However, Levi’s descendants are mentioned by name into the fourth generation. The text emphasizes the longevity of these men enabling them to educate and influence the third and fourth generation. The choice fruit were Moshe and Aharon, signifying their worthiness to be chosen as the leaders and spoke people for the Jews.
