Moshe Acts in Three Places

שמות ב ,יא: וַיַרְ א אִיש מִצְרִ י מַכֶה אִיש־עִבְרִ י מֵאֶחָיו

The Sforno notes that when a brother was attacked by a stranger, Moshe reacted with alacrity to defend and punish. When two Jews were involved (v. 13), Moshe admonished them. When it was two strangers (v. 17) Moshe neither punished or admonished, but defended the weak and oppressed.

These three episodes are presented by the Torah to teach us how one should react to events but the reaction needs to be dependent on the circumstances.