Abdullah bin Mubarak عبد الله بن المبارك · The Book of ar-Ruqba

"My father narrated to us: Ubaidullah -he is, Ibn 'Amr- narrated to us, from Sufyan, from Ibn Abi Najih, from Tawus, from Zaid bin Thabit, that the Prophet said: 'Ar-Ruqba is permissible.'"

"Do not give away your property on the basis of Ruqba, for whoever gives a gift on that basis, it belongs to the one to whom he gave it."

"The Messenger of Allah said: 'Umra (life-long gift) is permissible for the one to whom it is given, and Ruqba is permissible to the one to whom it is given, and the one who takes back his gift is like the one who goes back to his vomit.'"

"'Umra and Ruqba are the same."

"'Umra (a gift given for life) belongs to the heir."