He said...
He said: By no means, so go you both with Our signs; Surely We are with you, hearing.” [Holy Quran, as-Shuara; The Poets, Shakir 26:10-15] The act of Musa (A) whereby he killed a Copt is mentioned in the following ayats of Surah Qasas: “And he went into the city at a time of un-vigilance on the part of its people, so he found therein two men fighting, one being of his party and the other of his foes, and he who was of his party cried out to him for help against him who was of his enemies, So Musa struck him with his fist and killed him.
He said: This is on account of the Shaitan’s doing; surely he is an enemy, openly leading astray. He said: My Lord! Surely I have done harm to myself so do Thou protect me. So He protected him; surely He is the Forgiving, the Merciful. He said: My Lord! Because Thou hast bestowed a favor on me, I shall never be a backer of the guilty. And he was in the city, fearing, awaiting, when lo! he who had asked his assistance the day before was crying out to him for aid.