Musnad Abu Ya'la al-Mawsili 117:76

Abu Ya'la Ahmad ibn Ali ibn al-Muthanna al-Mawsili informed us, Abu al-Rabi' al-Zahrani narrated to us, Hammad ibn Zayd narrated to us, Thabit narrated to us, he said: I think it is from Anas, he said: There was a young boy from the Jews who used to serve the Prophet, may Allah bless him and grant him peace. He became ill, so the Prophet came to visit him, and his father was at his head. The Prophet, may Allah bless him and grant him peace, called him [to Islam]. The boy began looking at his father, so his father said to him: "Obey Abu al-Qasim." He said: "I bear witness that there is no god but Allah, and I bear witness that Muhammad is the Messenger of Allah." Then the boy perished. The Messenger of Allah, may Allah bless him and grant him peace, went out saying: "Praise be to Allah who saved him from the Fire through me."