Muhammad bin Muslim bin Tadras محمد بن مسلم بن تدرس أبو الزبير · The Book of 'Umra

It was narrated from Tawus that the Messenger of Allah made 'Umra and Ruqba binding.

"'Umra is permissible."

"The Messenger of Allah forbade 'Umra and Ruqba." I said: "What is Ruqba?" He said: "When one man says to another: 'This belongs to you for the rest of your life.' But if you do that, it is permissible."

"I heard Qatadah narrating from 'Ata', from Jabir that the Prophet said: 'Umra is permissible.'"

"The Messenger of Allah said: 'Whoever is given something for the rest of his life, it belongs to him for as long as he lives and after he dies.'"