It was narrated from Tawus that the Messenger of Allah made 'Umra and Ruqba binding.
Hadith Referenceسنن نسائي / كتاب العمرى / 3757
Hadith Gradingالألبانی:صحيح لغيره | زبیر علی زئی:صحيح
Hadith Takhrij«انظر ما قبلہ (صحیح) (طاؤس نے اسے مرسل روایت کیا ہے، لیکن سابقہ حدیث سے تقویت پاکر یہ صحیح لغیرہ ہے)»
Brief Explanation
1؎: That is, if someone gives something to another as ‘umra or ruqba, then the Messenger of Allah (sallallahu alayhi wa sallam) has separated it from the giver (wahib), so now he is not entitled to take it back. The one to whom it is given will have permanent ownership; after his death, his heirs will be entitled to it.