´It was narrated that Ibn 'Umar said:` "The Messenger of Allah said: 'Whoever swears, let him not swear by anything other than Allah.'" The Quraish used to swear by their forefathers, and so he said: "Do not swear by your forefathers."
Hadith ReferenceSunan an-Nasa'i / The Book of Oaths and Vows / Hadith: 3795
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:متفق عليه