Sayyiduna Abu Huraira (may Allah be pleased with him) narrated from the Messenger of Allah (peace and blessings be upon him), he (peace be upon him) said: "‘Umra (gifting something to someone for the duration of his life) is inheritance for his heirs. Or it is permissible for his heirs."
Hadith Referenceمسند اسحاق بن راهويه / كتاب الهبة و فضلها / 484
Hadith Takhrij«مسلم ، كتاب الهبات ، باب العمري ، رقم : 1262 . سنن ابوداود ، رقم : 3548 . سنن ترمذي ، رقم : 1349 .»