"His hands will fight for him": in killing Esav. "And You shall be a help against his foes": as in his standing up against Joseph (Bereshith 44:18).
Variantly: "And this, for Judah. And he said: Hear, O L-rd, the voice of Judah": We are hereby taught that Moses prayed for the tribe of Shimon [(Shimon not being explicitly mentioned here)], saying: "L-rd of the world, whenever the tribe of Shimon is in distress, rescue him from it.
"And to his people shall You bring him": For he (Judah) had drawn him (Shimon) near to himself for inheritance (of the land), as it is written (Judges 1:3) "and Judah said to Shimon his brother: "Go up with me (in battle) for my portion." And sections fell (for inheritance) from the inheritance of the children of Judah to that of the children of Shimon (viz. Joshua 19:9).