Maliks Muwatta Book 38, Hadith Number 11.

Section : Slaves Permitted to be Freed when a Slave must be Freed by Obligation.

Malik related to me that he had heard that Fadala ibn Ubayd al-Ansari who was one of the companions of the Messenger of Allah, may Allah bless him and grant him peace, was asked whether it was permissible for a man who had to free a slave to free an illegitimate child. He said, “Yes, That will give satisfaction for him.”