Sahih Muslim Book 009, Hadith Number 3506.
Chapter: Mere giving of option of divorce to women does not make divorce effective, but when it is really intended.
Jabir b. 'Abdullah (Allah be pleased with them) reported: Abu Bakr (Allah be pleased with him) came and sought permission to see Allah's Messenger (may peace be upon him). He found people sitting at his door and none amongst them had been granted permission, but it was granted to Abu Bakr and he went in. Then came 'Umar and he sought permission and it was granted to him, and he found Allah's Apostle (may peace be upon him) sitting sad and silent with his wives around him. He (Hadrat 'Umar) said: I would say something which would make the Holy Prophet (may peace be upon him) laugh, so he said: Messenger of Allah, I wish you had seen (the treatment meted out to) the daughter of Khadija when you asked me some money, and I got up and slapped her on her neck. Allah's Messenger (may peace be upon him) laughed and said: They are around me as you see, asking for extra money. Abu Bakr (Allah be pleased with him) then got up went to 'Aisha (Allah be pleased with her) and slapped her on the neck, and 'Umar stood up before Hafsa and slapped her saying: You ask Allah's Messenger (may peace be upon him) which he does not possess. They said: By Allah, we do not ask Allah's Messenger (may peace be upon him) for anything he does not possess. Then he withdrew from them for a month or for twenty-nine days. Then this verse was revealed to him: "Prophet: Say to thy wives... for a mighty reward" (xxxiii. 28). He then went first to 'Aisha (Allah be pleased with her) and said: I want to propound something to you, 'Aisha, but wish no hasty reply before you consult your parents. She said: Messenger of Allah, what is that? He (the Holy Prophet) recited to her the verse, whereupon she said: Is it about you that I should consult my parents, Messenger of Allah? Nay, I choose Allah, His Messenger, and the Last Abode; but I ask you not to tell any of your wives what I have said He replied: Not one of them will ask me without my informing her. God did not send me to be harsh, or cause harm, but He has sent me to teach and make things easy.