If an enslaved woman is purchased by a merchant's slave, and then the merchant takes possession, is *istibra'* required again for the merchant?

Primary text

If a merchant's slave purchases an enslaved woman and performs *istibra'*, and the woman then passes to the master, she is permissible to the master without a new *istibra'*, because his ownership remains established over what is in his slave's possession, meaning the purification occurred within his ownership domain.