A person cannot simply emancipate someone else’s property. In the textbook’s scenario, the fa links the response to the preceding sale offer, permitting an implied sequence: first accepting the purchase, then declaring its consequence.
Express words: the declaration of freedom.
Implied step: acceptance of the offered purchase.
Why needed: the intended consequence presupposes ownership.
This illustrates iqtida’: a necessary unstated component is supplied for the utterance to have its intended legal sense. The effect depends on the transaction context, not fa in isolation.