Musannaf Ibn Abi Shayba 36:7

Qarrad Abu Nuh narrated to us, he said: Yunus ibn Abi Ishaq informed us, from Abu Bakr ibn Abi Musa, from his father, who said: Abu Talib went out to Ash-Sham, and the Messenger of Allah (peace and blessings of Allah be upon him) went out with him, along with elders from Quraysh. When they overlooked the monk, they descended and unloaded their baggage. The monk came out to them, whereas before that they used to pass by him and he would not come out to them nor pay them any attention. He said: While they were unloading their baggage, he began moving among them until he came and took the hand of the Messenger of Allah (peace and blessings of Allah be upon him) and said: "This is the master of the worlds. This is the Messenger of the Lord of the worlds. Allah will send him as a mercy to the worlds." The elders of Quraysh said to him: "What is your evidence?" He said: "When you appeared from the mountain pass, there remained neither tree nor stone but that it fell down prostrating, and they do not prostrate except for a prophet. And I recognize him by the seal of prophethood below the cartilage of his shoulder, like an apple." Then he returned and prepared food for them. When he brought it to them, and he (the Prophet) was tending to the camels, he said: "Send for him." So he came, and there was a cloud shading him. He said: "Look at him, there is a cloud shading him." When he drew near to the people, he found they had already preceded him to the shade of the tree. When he sat down, the shade of the tree inclined over him. He said: "Look at the shade of the tree, it has inclined over him." He said: While he was standing over them, he was adjuring them not to take him to the Romans, for if the Romans saw him, they would recognize him by his description and kill him. He turned around, and behold, there were nine men who had come from the Romans. He went to meet them and said: "What brought you?" They said: "We came because this Prophet is to emerge this month. There is no road but that people have been sent to it, and we were informed of his news, so we were sent to this road of yours." He said to them: "Did you leave anyone behind you who is better than you?" They said: "No, we were only informed of his news, so we were sent to this road of yours." He said: "Do you see a matter that Allah wishes to decree, can any of the people prevent it?" They said: "No." He said: "So they pledged allegiance to him and stayed with him." Then he came to them and said: "I adjure you by Allah, which of you is his guardian?" Abu Talib said: "I am." He continued to adjure him until Abu Talib sent him back, and Abu Bakr sent Bilal with him, and the monk provided him with provisions of biscuits and oil.