It was narrated that Jabir said: “A slave came and pledged to the Prophet صلی اللہ علیہ وآلہ وسلم to emigrate, and the Prophet صلی اللہ علیہ وآلہ وسلم did not realize that he was a slave. Then his master came looking for him. The Prophet صلی اللہ علیہ وآلہ وسلم said: ‘Sell him to me,’ and he bought him for two black slaves. Then he did not accept the pledge from anyone until he asked: ‘Is he a slave?” (Sahih)