It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Whoever is given something as an umra (a life grant), it belongs to him and, after him, to his descendants as well."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Muhammad bin Amr except Abu Bakr bin Ayyash; Ahmad bin Yunus is alone in narrating it."