What is the ruling if the possessor admits ownership of one slave, but Zaid claims the other slave?

Primary text

If Zaid asserts, "Only the other slave belongs to me," the statement of the admitting party, coupled with their oath regarding the slave they deny ownership of, prevails. In one legal opinion, the slave admitted as belonging to Zaid remains in the possessor's custody because the admission was not properly established in favor of Zaid. In a second opinion, the slave is removed from the possessor's possession due to the admission that they do not own it, and the slave is placed in the public treasury (Bayt al-Mal) as it has no known owner, resembling unclaimed inheritance.