Abu Yusuf and Muhammad do not impose retrospective repetition merely because a carcass is discovered without knowledge of when it fell.
Their reasoning relies on the continued presumption of past purity: a later doubt does not undo an established state of purity. Consequences attach to the period proven to be affected.
Opening interactive controls...
Impurity in Wells and Rules of Drawing Water
Abu Yusuf and Muhammad do not impose retrospective repetition merely because a carcass is discovered without knowledge of when it fell.
Their reasoning relies on the continued presumption of past purity: a later doubt does not undo an established state of purity. Consequences attach to the period proven to be affected.