What does Exodus 2:14 mean?

Moses has attempted to break up a fight between two of his fellow Hebrews. One of the Jewish fighters answers the question of Moses with his own questions, calling out two points of hypocrisy. First, Moses was a Jew and yet lived among the Egyptians. Socially, at least, he was the last person with any authority to make judgments among the Hebrews. Moses was also a prince in one sense, since Pharaoh's daughter had adopted him into the royal family. He may have even been dressed in Egyptian clothing, further separating him from the culture of his own people. The question, then, can be re-phrased simply as "who are you to get involved in this?"

Second, the man implies that he knows about Moses' recent killing of an Egyptian who was beating a Hebrew (Exodus 2:11–12). This second point of hypocrisy questions how Moses can criticize violence when he himself has acted violently.

This second question is the one which strikes fear into the heart of Moses. His crime was known. Moses can now be put to death himself (Exodus 2:15). Instead of worrying about the fight between the two Jews, Moses was now in fear for his own life. His courage had turned to fear as Moses faced a crisis in which he must now face the consequences of his actions, or try to escape.