Ibn ‘Umar said the greatest oath the Prophet (ﷺ) used was, “No, by Him who overturns the hearts.” Bukhari transmitted it.

‘Abd ar-Rahman b. Samura reported God's Messenger as saying, “Do not swear by idols or by your fathers.” Muslim transmitted it.

Abu Huraira reported God’s Messenger as saying, "If anyone swears an oath and considers something else to be better than it he should make atonement for his oath and do that.” Muslim transmitted it.

He reported God’s Messenger as saying, "Your oath should be about something regarding which your companion will believe you.” Muslim transmitted it.

He reported God's Messenger as saying, "An oath is to be interpreted according to the intention of the one who takes it.” Muslim transmitted it.

Ibn Umar told that he heard God’s Messenger say, “He who swears by anyone but God is a polytheist.” Tirmidhi transmitted it.

Buraida reported God’s Messenger as saying, “He who swears by faithfulness* is not one of our number.” Abu Dawud transmitted it. * Amana. It is held that the objection is due to the fact that the word is not the name of one of God's attributes, but merely one of the duties prescribed to mankind. It is an unsuitable word because its use suggests that it is being equated with one of God’s attributes.

He reported God’s Messenger as stating that if anyone says, “I am free from Islam,” that is just as he has said if he is lying, but if he is speaking the truth he will not return safely to Islam. Abu Dawud, Nasa’i and Ibn Majah transmitted it.

Abu Sa'id al-Khudri told that when God’s Messenger swore strongly he said, “No, by Him in whose hand is the soul of Abu Qasim.” Abu Dawud transmitted it.

Abu Huraira said that when God’s Messenger swore an oath it was, “No, and I ask forgiveness of God.” Abu Dawud and Ibn Majah transmitted it.

Ibn ‘Umar reported God’s Messenger as stating that if anyone says when swearing an oath, “If God will”, he is not held accountable if he breaks it. Tirmidhi, Abu Dawud, Nasa’i, Ibn Majah and Darimi transmitted it, but Tirmidhi mentioned a number who traced it no farther back than Ibn ‘Umar.

Abul Ahwas ‘Auf b. Malik quoted his father as saying: I said, “Messenger of God, tell me what I should do about a cousin of mine to whom I go and ask for something, but who neither gives me anything nor regards my kinship, then when he needs my help comes to me and asks for something, and I have sworn that I would not give him anything or regard his kinship.” He commanded me to do that which is better and make atonement for my oath. In Ibn Majah’s version he told that he said, “Messenger of God, my cousin comes to me and I swear that I will not give him anything or regard his kinship,” and that he replied, “Make atonement for your oath.” Nasa’i and Ibn Majah transmitted it.

‘A’isha reported God’s Messenger as saying, “If anyone vows to obey God let him obey Him, but if anyone vows to disobey Him let him not disobey Him.” Bukhari transmitted it.

‘Imran b. Husain reported God's Messenger as saying, “A vow to do an act of disobedience must not be fulfilled, or one to do something over which one has no control.” Muslim transmitted it. A version has, “No vow must be taken to disobey God.”

‘Uqba b. ‘Amir reported God’s Messenger as saying, “The atonement for a vow is the same as for an oath.” Muslim transmitted it.

Ibn ‘Abbas said: While the Prophet (ﷺ) was preaching a man was standing, so he asked about him and was told that he was Abu Isra’il who had taken a vow to stand and not to sit, or go into the shade, or speak, but to fast. Thereupon the Prophet (ﷺ) said, “Command him to speak, go into the shade, sit and complete his fast.” Bukhari transmitted it.

‘A'isha reported God’s Messenger as saying, “No vow must be taken to do an act of disobedience, and the atonement for it is the same as for an oath.” Abu Dawud, Tirmidhi and Nasa’i transmitted it.

Ibn ‘Abbas reported God’s Messenger as saying, “If anyone takes a vow but does not name it, its atonement is the same as that for an oath; if anyone takes a vow to do an act of disobedience, its atonement is the same as that for an oath; if anyone takes a vow he is unable to fulfil, its atonement is the same as that for an oath; but if anyone takes a vow he is able to fulfil, he must do so.” Abu Dawud and Ibn Majah transmitted it, but some traced it no farther back than Ibn ‘Abbas.

Thabit b. ad-Dahhak said that in the time of God's Messenger a man took a vow to slaughter camels at Buwana and came and told him. God’s Messenger asked whether the place contained any idol worshipped in pre-Islamic times and was told that it did not. He asked whether any pre-Islamic festival was observed there and was told that no such thing was observed. He then said to the man, “Fulfil your vow, for a vow to do an act of disobedience to God must not be fulfilled, neither must one to do something over which a human being has no control.” Abu Dawud transmitted it.

‘Amr b. Shu'aib, on his father’s authority, said that his grandfather told of a woman who said, “Messenger of God, I have taken a vow to play the tambourine over you,” to which he replied, “Fulfil your vow.” Abu Dawud transmitted it. Razin added that she said, “And I have taken a vow to perform a sacrifice in such and such a place,” a place in which people had performed sacrifices in pre-Islamic times. He asked whether that place contained any idol worshipped in pre-Islamic times, and she replied that it did not. He asked whether any pre-Islamic festival was observed there, and she replied that none was. He then said, “Fulfil your vow.” Razin