Charles Ellicott Commentary Exodus 2:17

"And the shepherds came and drove them away; but Moses stood up and helped them, and watered their flock." — Exodus 2:17 (ASV)

The shepherds came. —Those of the neighbourhood. The rule of the desert is that those who come to a well take their turns in the use of the water in the order of their arrival. But these rude shepherds declined to wait for their turn. It appears later on, by the question of Reuel, “How is it that you have come so soon today?” that this rude and unfair conduct of the shepherds was habitual.

Moses stood up and helped them. —Moses is again the champion of the oppressed, but has learned wisdom from the past, and uses no unnecessary violence. His air and manner intimidated the wrongdoers, and they allowed the young women's sheep to be watered first.