And it was narrated to us by Yahya ibn Yahya, and Yahya ibn Ayyub, and Qutaybah, and Ibn Hujr. Yahya ibn Yahya said: "We were informed," while the others said: "It was narrated to us," by Isma'il—namely, Ibn Ja'far—from 'Abdullah ibn Dinar, that he heard Ibn 'Umar say: The Messenger of Allah, peace and blessings be upon him, said: "Whoever swears an oath, let him swear only by Allah." And the Quraysh used to swear by their fathers, so he said: "Do not swear by your fathers."