Musnad Ahmad 920:12

Abdullah narrated to us, he said: Muhammad ibn Ya’qub Abu al-Haytham al-Ribali narrated to us, Mu’tamir ibn Sulayman narrated to us, he said: I heard my father, Raqabah narrated to us, from Abu Ishaq, from Sa’id ibn Jubayr, from Ibn Abbas, Ubayy ibn Ka’b narrated to us, he said: I heard the Prophet of Allah, peace and blessings of Allah be upon him, saying: "While Moses was among his people, reminding them of the days of Allah—and the days of Allah are His blessings and His trials—he said: 'I do not know of any man on earth better than me, or more knowledgeable than me.' He said: 'So Allah revealed to him: "I know better who is the best, or with whom it is; there is a man on earth who is more knowledgeable than you." He said: "O Lord, then guide me to him." It was said to him: "Take a salted fish as a provision." He did so, then he set out, and he met al-Khidr, and their affair was what it was, until the end of that: they passed by a village whose people were ignoble. They went around the gatherings and asked for food, but they refused to host them. Then he narrated to him the news, the news of the ship, and that he only pierced it so that the king might pass it by, and he would not want it. As for the boy, he was created on the day he was created as a disbeliever; his parents were affectionate toward him, and had he reached maturity, he would have burdened them with transgression and disbelief. And as for the wall, it belonged to two orphan boys in the city."