What is the ruling on a father taking back a gift given to his son with the intention of revocation?

Primary text

If a father takes back what he gifted to his son and intends that action as revocation, it is indeed a revocation. The father's statement regarding his intention is accepted. If it is unclear whether he intended revocation, and this occurs after the father's death, revocation is not established unless there is accompanying evidence (qara'inah) indicating revocation, as taking back the item is ambiguous. If evidence supporting revocation is present, there are two views: the first, preferred by Ibn 'Aqil, holds that it is a valid revocation because the state of affairs suffices to indicate intent, just as it suffices in the contract itself. The second view, held by Al-Shafi'i, states it is not a revocation because the ownership is definitively established for the recipient and can only be removed by explicit wording.