Sufyan bin 'Uyaynah سفيان بن عيينة · The Book of Oaths and Vows

"There is nothing on Earth that I swear an oath upon, and I see that something else is better, but I do that which is better."

"The Messenger of Allah said: 'A vow does not bring anything forward or put it back; it is just a means of taking wealth from the miserly.'"

"I heard the Messenger of Allah say: 'Whoever vows to obey Allah, let him obey Him, and whoever vows to disobey Allah, let him not disobey Him.'"

"The Prophet passed by a man who was circumambulating the Ka'bah, led by another man with a reign in his nose. The Prophet took him by the hand and commanded him to lead him by his hand." Ibn Juraij said: "Sulaiman told me that Tawus told him, from Ibn 'Abbas, that the Prophet passed by him when he was circumambulating the Ka'bah, and a man had tied his hand to another man with some string or thread or whatever. The…

It was narrated from Ibn 'Umar, that 'Umar had vowed to spend a night in 'Itikaf during the Jahiliyyah. He asked the Messenger of Allah about that, and he ordered him to perform the 'Itikaf.

"The Messenger of Allah said: 'There is no vow at a moment of anger and its expiation is the expiation for an oath.'"