Or HaChaim on Exodus 2:15/אור החיים על שמות ב׳:ט״ו

1 את הדבר הזה, this matter, etc. Moses used the word הזה, to indicate that it was only after this aggressive Jew had said to Moses: "are you going to kill me also, etc." that he realised with certainty that he had observed him killing the Egyptian.

2ויבקש להרוג אותו. He tried to kill him. This means that Pharaoh tried to establish proof that Moses had killed the Egyptian as a result of which he would be brought to trial and be executed. This is why Moses fled from Pharaoh in case Pharaoh would obtain enough proof to make him stand trial. On the other hand, the words מפני פרעה may refer to Pharaoh's face. When Moses looked at Pharaoh's angry face he realised that he was in danger and fled even though he did not know what Pharaoh knew and what he did not.