Sahih Bukhari Volume 2, Book 23, Hadith Number 406.

Narated By Jabir bin ‘Abdullah  : The Prophet said, “Today a pious man from Ethiopia (i.e. An Najashi) has expired, come on to offer the funeral prayer.” (Jabir said): We lined up in rows and after that the Prophet led the prayer and we were in rows. Jabir added, I was in the second row.”