'Amro bin Shu’aib narrated on the authority of his father, on the authority of his grandfather (RAA), That the Messenger of Allah ( صلی اللہ علیہ وسلم ) said:“A slave who entered into an agreement to buy his freedom is still a slave as long as a Dirham of the agreed price remains to be paid.”Related by Abu Dawud with a good chain of narrators. The full hadith is related by Ahmad and the three Imams. Al-Hakim graded it to be Sahih.