Sunan Abi Dawud, 3926

Narrated 'Amr b. Shu'aib: on his father's authority, told that his grandfather reported the Prophet (ﷺ) said: A slave who has entered into an agreement to purchase his freedom is a slave as long as a dirham of the agreed price remains to be paid

Rapporté par ‘Amr ibn Shu‘aib, d’après son père, qui le tient de son grand-père : Le Prophète ﷺ a dit : « Un esclave qui a conclu un contrat pour acheter sa liberté reste esclave tant qu’il reste un dirham à payer du prix convenu. »