Sahih Bukhari | Volume 3 | Hadith Number 707
Narrated by Qais
When Abu Huraira accompanied by his slave set out intending to embrace Islam they lost each other on the way. The slave then came while Abu Huraira was sitting with the Prophet. The Prophet said, "O Abu Huraira! Your slave has come back." Abu Huraira said, "Indeed, I would like you to witness that I have manumitted him." That happened at the time when Abu Huraira recited (the following poetic verse): 'What a long tedious tiresome night! Nevertheless, it has delivered us From the land of Kufr (disbelief).