A conditional expression may use acquiring ownership to refer to ownership obtained by purchase. Conversely, mention of purchase may allude to the resulting ownership.
«إن ملكت عبدا فهو حر»
If I acquire ownership of an enslaved person, that person is free.
«إن اشتريت عبدا فهو حر»
If I purchase an enslaved person, that person is free.
Both examples call for analysis of the condition, the resulting legal consequence, and the intended meaning. Purchase and ownership have a real legal relationship, but the two words are not synonyms in all circumstances. Their interchange depends on the particular setting and intention.