Shu'bah bin al-Hajjaj شعبة بن الحجاج · The Book of Oaths and Vows

"The Messenger of Allah said: 'Do not swear by your fathers, nor by your mothers nor by the idols. Swear only by Allah, and do not swear unless you are sincere.'"

"We were talking about something, and I had only recently left Jahiliyyah behind, so I swore by Al-Lat and Al-'Uzza. The Companions of the Messenger of Allah said to me: 'What a bad thing you have said! Go to the Messenger of Allah and tell him, for we think that you have committed Kufr.' So I went to him and told him, and he said to me: 'Say: La ilaha illallah wahdahu la sharika lah (There is none worthy of…

"The Messenger of Allah commanded us to do seven things: He commanded us to attend funerals, visit the sick, to reply (say: Yarhamuk Allah ) to one who sneezes, to accept invitations, to support the oppressed, to fulfill oaths (when adjured by another) and to return greetings of Salaam."

"The Messenger of Allah said: 'If you swear an oath, then you see something that is better, then do that which is better and offer expiation for your oath.'"

"There is no vow and no oath concerning that which one does not possess, nor to commit sin, nor to sever the ties of kinship."

"In Al-Madinah we used to buy and sell Wasqs (of goods), and we used to call ourselves Samasir (brokers), and the people used to call us like that. The Messenger of Allah came out to us one day, and called us by a name that was better than that which we called ourselves and which the people called us. He said: 'O Tujjar (traders), your selling involves (false) oaths and lies, so mix some charity with it.'"

"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.'"

"Whoever swears by a religion other than Islam, telling a lie, will be as he said, and whoever kills himself with something, he will be punished with it in the Hereafter, and there is no vow concerning that which a man does not possess."

The Messenger of Allah said: "There is no vow to commit an act of disobedience and its expiation is the expiation for an oath." Mansur bin Zadhan contradicted him in his wording.

"The Messenger of Allah said: 'Whoever swears an oath and says: "If Allah wills, then he has made an exception."'"