Musnad Abu Ya'la al-Mawsili 75:1

'Afif said: I came during the Jahiliyyah to Makkah, and I wanted to buy for my family some of its garments and perfume. So I came to al-'Abbas ibn 'Abd al-Muttalib, and he was a merchant man. While I was sitting with him, looking at the Ka'bah, the sun had risen in the sky and ascended. Then, while I was there, a young man came, cast his gaze toward the sky, then stood facing the Qiblah. Then I did not wait but a little while until a boy came and stood on his right. Then I did not wait but a little while until a woman came and stood behind them. The young man bowed, and the boy and the woman bowed. The young man rose, and the boy and the woman rose. I said: "O 'Abbas, a momentous affair." Al-'Abbas said: "A momentous affair. Do you know who this young man is?" I said: "No." He said: "This is Muhammad ibn 'Abdullah, my brother's son. Do you know who this boy is? This is 'Ali, my brother's son. Do you know who this woman is? This is Khadijah bint Khuwaylid, his wife. This brother's son of mine informed me that his Lord, the Lord of the heavens and the earth, commanded him with this religion which he is upon. And by Allah, there is not on the entire earth anyone upon this religion except these three."