The Messenger of Allah ﷺ said, "Whoever grants a lifetime gift to a man and his descendants, it belongs to the one to whom it was given. It does not return to the one who gave it, because he made a gift in which the laws of inheritance have taken effect."
حدثنا محمد بن يحيى بن فارس ومحمد بن المثنى قالا حدثنا بشر بن عمر حدثنا مالك يعني ابن أنس عن ابن شهاب عن أبي سلمة
أن رسول الله ﷺ قال أيما رجل أعمر عمرى له ولعقبه فإنها للذي يعطاها لا ترجع إلى الذي أعطاها لأنه أعطى عطاء وقعت فيه المواريث
Muslim narrated it, in the chapter on Gifts, section on the "umra" gift, hadith no. 1625, from the hadith of Malik through this route. It is also found in Muwatta (Yahya's recension) 2/756. See also hadith no. 3550.