I heard the Messenger of Allah ﷺ say, "Whoever grants another person a lifetime gift for him and his descendants has by his own words severed his right to it. It belongs to the one to whom it was granted and to his descendants."
أخبرنا قتيبة بن سعيد قال حدثنا الليث عن ابن شهاب عن أبي سلمة بن عبد الرحمن
سمعت رسول الله ﷺ يقول من أعمر رجلا عمرى له ولعقبه فقد قطع قوله حقه وهي لمن أعمر ولعقبه