Zaynab bint Jahsh was married to Zayd ibn Haritha, the Prophet's adopted son, and later married the Prophet (peace and blessings be upon him). Critics say he desired his son's wife and that a revelation conveniently allowed it.
Zaynab was the Prophet's own cousin, whom he had known all her life. It was the Prophet who arranged her marriage to Zayd, a former slave whom he had freed and raised, and she and her family were reluctant because of Zayd's status. Dr. Hasan Ashraf (Yaqeen Institute) notes that if the Prophet had wished to marry her, he could simply have done so then, and her family would have welcomed it.
“Narrated Anas: Zaid bin Haritha came to the Prophet complaining about his wife. The Prophet kept on saying (to him), "Be afraid of Allah and keep your wife."”Sahih al-Bukhari 7420, grading: Sahih (in Sahih al-Bukhari). English translation as given on sunnah.com
And [remember, O Muḥammad], when you said to the one on whom Allah bestowed favor and you bestowed favor, "Keep your wife and fear Allah," while you concealed within yourself that which Allah is to disclose. And you feared the people, while Allah has more right that you fear Him. So when Zayd had no longer any need for her, We married her to you in order that there not be upon the believers any discomfort [i.e., guilt] concerning the wives of their claimed [i.e., adopted] sons when they no longer have need of them. And ever is the command [i.e., decree] of Allah accomplished.Quran 33:37, Sahih International
Allah has not made for a man two hearts in his interior. And He has not made your wives whom you declare unlawful your mothers. And He has not made your claimed [i.e., adopted] sons your [true] sons. That is [merely] your saying by your mouths, but Allah says the truth, and He guides to the [right] way. Call them by [the names of] their fathers; it is more just in the sight of Allah. But if you do not know their fathers - then they are [still] your brothers in religion and those entrusted to you. And there is no blame upon you for that in which you have erred but [only for] what your hearts intended. And ever is Allah Forgiving and Merciful.Quran 33:4-5, Sahih International
Muḥammad is not the father of [any] one of your men, but [he is] the Messenger of Allah and seal [i.e., last] of the prophets. And ever is Allah, of all things, Knowing.Quran 33:40, Sahih International
The Quran gives the purpose itself: to end the pre-Islamic custom that treated an adopted son as a son by blood, so that believers would be free to marry the former wives of adopted sons (Quran 33:37), and to establish that the Prophet was "not the father of any one of your men" (Quran 33:40). What the Prophet "concealed" was, in the explanation of Ali ibn al-Husayn (Zayn al-Abidin), that God had already told him Zaynab would become his wife; he held back out of fear of what people would say about marrying his adopted son's former wife. Al-Qadi Iyad called this the sounder view, and Ibn Hajar praised it.
“Aisha said, "If Allah's Messenger were to conceal anything (of the Qur'an he would have concealed this Verse." Zainab used to boast before the wives of the Prophet and used to say, "You were given in marriage by your families, while I was married (to the Prophet) by Allah from over seven Heavens."”Sahih al-Bukhari 7420, grading: Sahih (in Sahih al-Bukhari). English translation as given on sunnah.com
Aisha's remark shows that this verse, which rebukes the Prophet, was not a convenience to him. He recited it anyway.
The story that the Prophet saw Zaynab at her house and was struck by her comes from reports that Muslim hadith critics graded weak: through al-Waqidi, Muqatil ibn Sulayman and others, more than a century after the event. Ibn Kathir said he would leave these reports out entirely because they are not authentic, and Ibn al-Qayyim condemned those who accepted them. Dr. Hasan Ashraf traces how the story grew, partly by modelling it on the biblical account of David (peace be upon him) and Bathsheba, and shows that the earliest biographers of the Prophet, including Ibn Ishaq, do not mention it.
And if you fear that you will not deal justly with the orphan girls, then marry those that please you of [other] women, two or three or four. But if you fear that you will not be just, then [marry only] one or those your right hands possess [i.e., slaves]. That is more suitable that you may not incline [to injustice].Quran 4:3, Sahih International
And you will never be able to be equal [in feeling] between wives, even if you should strive [to do so]. So do not incline completely [toward one] and leave another hanging. And if you amend [your affairs] and fear Allah - then indeed, Allah is ever Forgiving and Merciful.Quran 4:129, Sahih International
The Quran limits a man to four wives, makes justice between them a condition, and warns that if he fears he cannot be just he should marry only one (Quran 4:3, 4:129). The Prophet's own household was governed by revelation specific to him (Quran 33:50), as Muslim scholars explain.
At evening, David arose from his bed and walked on the roof of the king’s house. From the roof, he saw a woman bathing, and the woman was very beautiful to look at. David sent messengers, and took her; and she came in to him, and he lay with her (for she was purified from her uncleanness); and she returned to her house. He wrote in the letter, saying, “Send Uriah to the forefront of the hottest battle, and retreat from him, that he may be struck, and die.”2 Samuel 11:2, 4, 15, World English Bible (public domain)
The critics' own scripture tells exactly the story they wrongly attach to the Prophet Muhammad, and worse. It says that David saw a married woman bathing, took her, and then arranged for her husband to be killed in battle. Muslims reject this account: the Quran honors David as a prophet who "repeatedly turned back" to God (Quran 38:17), and Islam holds that God's prophets did not commit such crimes. But those who accept 2 Samuel 11 as scripture still honor David. It is inconsistent to attack the Prophet over a story found only in weak reports while accepting a far worse one about David in their own Bible.
He had seven hundred wives, princesses, and three hundred concubines; and his wives turned away his heart.1 Kings 11:3, World English Bible (public domain)
If a man has two wives, the one beloved, and the other hated, and they have borne him children, both the beloved and the hated; and if the firstborn son is hers who was hated;Deuteronomy 21:15, World English Bible (public domain)
The Bible also records plural marriage without any limit: Solomon (peace be upon him) with seven hundred wives and three hundred concubines, and a law in the Torah that regulates a man with two wives rather than forbidding it. The Quran's limit of four, with justice as a condition, is a restriction, not a license.
Quran quotations: Sahih International via quran.com. Hadith quotations: the English translations and gradings shown on sunnah.com. Bible quotations: World English Bible (public domain).