Is it permissible to return a Muslim captive to the disbelievers?
General Chapter
Al-Mughni
Book of Jihad
Primary text
It is not permissible to return a Muslim captive to the disbelievers unless he has something that protects him from the polytheists, such as kinship or a similar connection.
Supporting text
Ransom was permitted for him only as a means to be released from slavery.