السلام عليكم
Is there any specific ahkam related to the re-enslavement of a kafir slave who was freed by his Muslim master but traveled and settled in the land of Dar al Harb & muslim seized him in Jihad or was captured by other Kuffar?
Is it permissible for the Muslims to buy and keep him/her as a slave or he must be set free?
Note: Slave is still Kafir