Sunan Ibn Majah Book 14, Hadith 7
the Prophet (ﷺ) ruled that a gift given for life belongs to the heirs (of the recipient).
“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.”
“There is no Ruqba. Whoever is given a gift on the basis of Ruqba, it belongs to him, whether he lives or dies.”