إن ملكت عبداً فهو حرٌّ
“If I come to own a slave, he is free.”
Suppose a person acquires one half-share in a slave, sells it, and later obtains the other half-share. At no point are both shares held together as one complete ownership.
Under this literal condition, the required ownership of the whole slave has not occurred. Acquiring two halves at different times is not equivalent to possessing the whole simultaneously.