Ali b. Ibrahim (ar) says (regarding the saying of Allah, “O Prophet! Why do you forbid (yourself) that which Allah has made lawful for you..- Surah Tahreem (66): Verse 1)
The reason for its revelation was that the Holy Prophet (sawa) when he was in the house of some of his wives and that Maariyah Qibtiyyah (ra) used to be there with him serving him. One day while he was there in the house of Hafsah and Hafsah went out for some need, then the Holy Prophet (sawa) had food with Maariyah (ra). When Hafsah (la) learnt of this, she became angry and came to the Holy Prophet (sawa) complaining - “O Messenger of Allah! This (you did) and that too on the day appointed for me and in my very house and on my very bed!”
The Holy Prophet (sawa) felt embarrassed. He (sawa) said, “Keep this to yourself. I have made Maariyah prohibited for myself and I will never partake food with her again. I am going to tell you a secret. If you disclose this secret, upon you will be the curse of Allah and the angels and all the people. She asked. “What is it?” He (sawa), “Surely Abu Bakr will be the caliph after me and after him will be your father.” She asked, “Who informed you of this?” He (sawa) replied, “Allah has informed me.”
Then Hafsah informed Ayesha about it who then informed Abu Bakr about it. Abu Bakr went to Umar and told him, “Surely Ayesha has informed me that Hafsah told her something, but I do not trust Ayesha’s words. So can you ask Hafsah about it.”
Then Umar went to Hafsah and asked her - “What is it that Ayesha is narrating from you?” She denied it and said “I have not informed Ayesha of any such thing.” Umar told her, “If this (news) is true, then confirm it for me so that we may proceed (in this matter)”. She said,
“Yes, the Holy Prophet (sawa) did say so”.
Then the four of them agreed to poison the Holy Prophet (sawa). Then Hazrat Jibraeel (as) descended with this chapter (of Tahreem) – “O Prophet! Why do you forbid (yourself) that which Allah has made lawful for you..upto the verse - expiation of your oaths”meaning certainly Allah has made it permissible for you that you do away with your oath.
