Sahih Muslim
The Book of Jihad and Expedition (Kitab Al-Jihad wal-Siyar)
Book Number: 019 / Hadith Number: 4383
The tradition has been narrated on the authority of Anas b. Malik (the same narrator) through a different chain of transmitters, but this version does not mention:" And he was not the Negus for whom the Prophet (may peace be upon him) had said the funeral prayers."