{ And when you said to him who Allah has graced and who you have graced: Keep your wife for yourself and fear Allah, you were hiding in yourself what Allah made clear, and you feared people; but Allah is most worthy that you should fear Him. And when Zaid fulfilled his desire from her, we married her to you, so that there would not be any uneasiness in the believers about the wives of their adopted sons once they have fulfilled their desire from them; and the order of Allah will be accomplished. There is no uneasiness on the Prophet concerning what Allah has prescribed for him; it is the way of Allah with those who have come before. And the order of Allah is destined and ordained } Al-ahzab 37-38

This came down concerning Zainab bint Jahsh and Zaid ibn Haritha. ‘Amr ibn Mas’ud, ‘Aishah, and Al-Hasan said: Allah did not send down on His Messenger a more intense verse for Him than this verse. Al-Hasan and ‘Aishah said: If the Messenger of Allah (SAW) would have suppressed anything of the revelation, He would have suppressed this verse due to how intense it was for Him. It is narrated in the report that Zaid came back one evening and headed for his bed. Zainab said: But Zaid couldn’t do it with me; I didn’t keep myself from him except that Allah kept him from me, and he was not able with me. This is the account from Abu ‘Asma Nuh ibn Abi Maryam who traced the hadith to Zainab that she said this. In other accounts it is related that Zaid’s thing would swell up whenever he desired to get close to her. This is related to the other account. So Zaid went to the Messenger of Allah (SAW) and said: Indeed Zainab harms me with her words over and over, and truly I wish to divorce her. He said to him { Keep your wife for yourself and fear Allah } from this verse. But Zaid divorced her, and this came down { when you said to him who Allah has graced and who you have graced } and the rest of the verse.
Muqatil said: The Prophet (SAW) married Zainab bint Jahsh to Zaid, and she remained with him for a time. Then He (peace be upon him) came looking for Zaid one day, and He noticed Zainab standing there; she was white, beautiful, corpulent, among the most perfect women of Quraish; and He desired her. And He said: Exalted is Allah who flips hearts upside down! And Zainab heard this exclamation of praise and mentioned it to Zaid. Zaid was quick to see what was going on, and said: Oh Messenger of Allah, give me permission to divorce her, for there is pride in her, she makes herself great above me, and she harms me with her words. But He (peace be upon him) said: Keep your wife and fear Allah. It was said that Allah sent a wind which lifted the curtain while Zainab was at ease loosely clothed in her room. And He saw Zainab and His heart fell for her, and Zainab became aware that the Prophet’s (SAW) heart had fallen for her; and this was when He had come looking for Zaid. Then Zaid came and she told him about this, and Zaid got the notion to divorce her.
Ibn ‘Abbas said: You have hidden love for her in your heart, and you fear people, in other words, you are ashamed of them; and it is said that you are afraid and are averse towards the imams of the Muslims. Even if you had said: Divorce her; and they said: He has ordered a man to divorce his woman; and then you had marital relations with her when he had divorced her, Allah is most worthy that you should fear him in all circumstances. It was also said: And Allah is most worthy that you be ashamed before him, so do not order Zaid to keep his wife after Allah has made it known to you that she is to be your wife. And Allah admonished Him over all of this.