Muwatta 2356

Malik said: every child a slave-woman bore who was bequeathed freedom but not made conditionally free, is not freed with her when she is freed, because her master may change his bequest if he wishes and retract it whenever he wishes, and her manumission was not established. This is like a man who said to his slave-girl: if so-and-so remains with me until I die, she is free. If she lives to see that, she is hers; if he wishes before that, he sells her and her child, because her child was not included in anything made for her. ¹

Belongs to the Muwatta, Book of the Conditionally Freed Slave (mudabbar). Source: the Muwatta. Mentions Malik ibn Anas. Built on in the chapters on conditional freedom (tadbir) and bequest (wasiyya).