When Moses reached full manhood and maturity, We bestowed upon him wisdom and knowledge: this is how We reward those who do good. 14 He entered the city unnoticed by its people, and there he encountered two men fighting with one another -- one of his own people and the other one of his enemies. The one who belonged to his own people cried out to him for help against his foe -- whereupon Moses struck him down with his fist, thereby causing his death. Moses said, "This is Satan's doing; he is an open foe, leading man astray." 15 He prayed, "Forgive me Lord, for I have sinned against my soul." God forgave him; for He is the Forgiving One, the Merciful. 16 He said, "My Lord, because of the favour that You have shown me, I vow that I will never be a helper of the guilty." 17 In the morning, he was in the city, fearful and vigilant, then he whom he had helped the day before cried out to him again for help. 'Clearly' said Moses, 'you are quarrelsome' 18 But then as soon as he was about to lay violent hands on the man who was their [common] enemy, the latter exclaimed: "O Moses, dost thou intend to slay me as thou didst slay another man yesterday? Thy sole aim is to become a tyrant in this land, for thou dost not care to be of those who would set things to rights!" 19 A man came running from the farthest part of the city saying, "Moses, people are planning to kill you. I sincerely advise you to leave the city. 20 So he escaped from there, looking about in a state of fear. He said: "My Lord! Save me from the people who are Zalimun (polytheists and wrong-doers)!" 21