It is narrated from Sayyiduna Abdullah bin al-Zubayr (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The umra (a thing given for life) is valid for the one to whom it is given, and the ruqba is likewise valid for the one to whom it is given, and its ruling is the ruling of inheritance."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13853