It is narrated from Sayyiduna Zayd bin Harithah (may Allah be pleased with him) that he said: The Messenger of Allah (peace and blessings be upon him), with me riding behind him, set out towards one of the (idols') altars, and we slaughtered a sheep for it, then cooked it in a pit (of heated stones). When it was cooked, we took it out and put it in our provision bag. Then the Messenger of Allah (peace and blessings be upon him) mounted his she-camel, with me riding behind him. When we were in the upper part of Makkah, Zayd bin Amr bin Nufayl met him, and each of them greeted the other with the greeting of the Days of Ignorance. The Messenger of Allah (peace and blessings be upon him) said to him: "What is the matter? I see that your people have come to hate you and feel aversion to you." He said: By Allah, that is not because of any hostility on my part towards them; rather, I see them in misguidance, so I went out in search of this religion. I reached the scholars of Khaybar and found that they worship Allah but also associate partners with Him. I said: By Allah, this is not the religion I am seeking. So I went on until I reached the scholars of Syria, and found that they too worship Allah and associate partners with Him. I said: By Allah, this too is not the religion I set out to seek. At that, one of the scholars of Syria said: You are asking about a religion which we know of no one practising except one person in the Arabian Peninsula. So I went on until I reached him and told him what I had set out for. He said to me: All the people you have seen are in misguidance. You are asking about the religion of Allah and His angels, and a prophet has appeared in your land, or is about to appear, so go back, affirm his truth and believe in him. So I came back, but I have not yet come to know of any prophet. He said: Then the Messenger of Allah (peace and blessings be upon him) made his she-camel kneel, and the provision mat was placed before him. Zayd bin Amr asked: What is this? He was told: "This is a sheep that we slaughtered in the name of such-and-such an idol." Zayd bin Amr said: I do not eat anything that has been slaughtered in the name of other than Allah. Then we parted. He said: And Zayd bin Amr bin Nufayl died before the Messenger of Allah (peace and blessings be upon him) was sent as a prophet, and the Messenger of Allah (peace and blessings be upon him) said: "On the Day of Resurrection he will be raised as a nation by himself."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 4647