The lifetime gift (umra) which the Messenger of Allah ﷺ permitted is when the giver says, "It is for you and your descendants." But if he says, "It is yours for as long as you live," then it returns to its original owner.
حدثنا عبد الرزاق أخبرنا معمر عن الزهري عن أبي سلمة بن عبد الرحمن
إنما العمرى التي أجاز رسول الله ﷺ أن يقول هي لك ولعقبك فأما إذا قال هي لك ما عشت فإنها ترجع إلى صاحبها
Its isnad is sahih. Abu Salama bin Abdul-Rahman's name is actually his kunya, according to the correct view, and he is trustworthy and excellent.The hadith was narrated by Muslim, 3/1246, no. 1625, in the chapter on gifts, under "The Life-Grant," and by Abu Dawud, 3/820, no. 3555, Abu Hafs edition, in the chapter on sales, under "Whoever Says, 'It Is His and His Descendants'."