(5) باب الْحَلِفِ بِالآبَاءِ
It was narrated from Salim, from his father, that he told him from 'Umar:
"The Messenger of Allah said: 'Allah forbids you to swear by your forefathers.'" 'Umar said: "By Allah, I never swore by them again, whether saying it for myself or reporting it of others."
Reference: Sunan an-Nasa'i 3768
In-book reference: Book 35, Hadith 8
English translation: Vol. 4, Book 35, Hadith 3799