Salim bin Abdullah bin Umar reported,
People of Iraq, how is it that you ask about minor matters while you commit grave ones with such ease? I heard my father Abdullah bin Umar say, "I heard the Messenger of Allah ﷺ say, 'Tribulation comes from here,' and he pointed with his hand toward the east, 'from where the two horns of Satan rise. Yet here you are, striking off one another's heads. Musa killed the man from the family of Pharaoh by mistake, and Allah 
said to him, "And you killed a soul, but We saved you from distress and tried you with a severe trial" [Ta-Ha 20:40].'"
Azami 12725
Sahihعن سالم بن عبد الله بن عمر يقول
يا أهل العراق! ما أسألكم عن الصغيرة، وأركبكم للكبيرة، سمعت أبي عبد الله بن عمر يقول: سمعت رسول الله ﷺ يقول: إن الفتنة تجيء من ها هنا. وأوما بيده نحو المشرق: من حيث يطلع قرنا الشيطان. وأنتم يضرب بعضكم رقاب بعض، وإنما قتل موسى الذي قتل من آل فرعون خطأ، فقال الله عز وجل له: {وقتلت نفسا فنجينك من الغم وفتنك فتونا}
Muslim narrated it in the Book of Tribulations and Signs of the Hour (29:2905), through several routes, from Ibn Fudayl, from his father, who said, I heard Salim bin Abdullah bin Umar say, then he related it.Allah Almighty did not specify the type of soul that was killed, but it is established in the Israelite traditions that the man killed was an Egyptian from the household of Pharaoh, and this is also confirmed with us, as in the following hadith.Regarding His statement, "And We tried you with a trial" [Qasas 28:40], meaning, We tested you and examined you from your birth, and found you patient and steadfast. In detail, when he was born, he was cast into the river, and when he reached maturity, he found two men fighting, one an Egyptian Copt and the other an Israelite Hebrew. The Israelite called on him for help against the Copt, so Musa struck the Egyptian and killed him, and rescued his Israelite brother. Musa said, when he had killed the man, not having intended to kill him, "This is from the work of Satan. He is indeed a misleading enemy, manifest" [Qasas 28:15]. Then he said, "My Lord, indeed I have wronged myself, so forgive me. So He forgave him. Indeed, He is the Forgiving, the Merciful" [Qasas 28:16].So he became, in Madinah, fearful, watching for news. Then Musa saw that same Israelite the next day fighting another man from the household of Pharaoh, and the Israelite called on him for help against the Egyptian. Musa was remorseful over what he had done the day before, so he became angry with the Israelite, who wanted him to kill the Egyptian again that day. Musa said to him, "Indeed, you are clearly astray" [Qasas 28:18]. The Israelite feared for himself and said, "O Musa, do you intend to kill me as you killed a man yesterday" [Qasas 28:19]. So the news spread that Musa was the one who had killed the Egyptian the day before.So Musa fled from Pharaoh and his people when they intended to kill him, and he headed toward Madyan, saying, "Perhaps my Lord will guide me to the right way" [Qasas 28:22].