It was narrated from Salim bin 'Abdullah, that his father said: "I heard 'Umar bin Al-Khattab say: 'The Messenger of Allah (s.a.w) said: "Allah, may He be exalted, forbids you to swear by your fathers." 'Umar said: "By Allah, I have not sworn by them since I heard the Messenger of Allah (s.a.w) forbid that, whether on my own behalf or narrating it from someone else."