Sunan Ibn Majah Book 14, Hadith 5
“There is no lifelong grant. Whoever is given something as a lifelong grant, it is his.' ”
“None of you should take back his gift, except a father (taking it back) from his son.”
“I heard the Messenger of Allah (ﷺ) say: 'Whoever gives a lifelong grant to a man, it belongs to him (the recipient) and to his heirs. His (the giver's) words put an end to his right to it, and it belongs to the one to whom it was given for life and to his heirs.”