As to why the Prophet (S.A) concealed this information in his heart, some commentators have stated that it was on account of the fact that due to the ignorance and arrogance of the Arabs, they would use remarks against him for marrying the wife of his son (when in reality, it was not the wife of his son). Although the Quran had already condemned the custom of regarding an adopted son as a son, the unbelieving Arabs still had this custom in their hearts. The Prophet (S.A) therefore, did not reveal this to anyone out of modesty and bashfulness, and also to protect his honour from the taunts of the people.
While this occurred in the heart of the Prophet (S.A), Allah revealed these verses in the Holy Quran to make this matter manifest, since it was His decree that Zainab bint Jahsh (R.A) will be married to the Prophet (S.A). This marriage was decreed by Allah and had to come to pass regardless of the taunts and feelings of the unbelievers. Through this marriage, Allah abolished a custom which was held by the Arabs where they considered the wife of an adopted son to be the same as the wife of a real son. By decreeing the marriage of Zainab (R.A) to the Prophet (S.A), Allah showed that it was permissible for one to marry the wife of an adopted son, after she has come out of that marriage. (Safwatut Tafseer vol.13 pg. 62; Tafseer Al Qurtubi vol.14 pg. 167; Ma’ariful Quran vol.7 pg. 165; Anwarul Bayaan vol.4 pg. 241)
In the verse (37) it was said to the Prophet (S.A) ‘you did fear the people whereas Allah had a better right that you should fear Him’. This referred to the fear that the Prophet (S.A) had that some people would object to such a marriage. However, when Allah revealed the verse, ‘Allah has not made your adopted sons (as) your own sons’, there remained no doubt that a man was allowed to marry his adopted son’s former wife. When Allah has declared something lawful, no objection to it will be considered.
To remove the doubts and the old custom from the minds of the people, it was necessary that the injunction be pronounced verbally and practically by the Holy Prophet (S.A). Hence, Allah decreed the marriage between him and Zainab bint Jahsh so that this old custom can be totally abolished. (Anwarul Bayaan vol.4 pg. 242)
The Prophet (S.A) was told in the verse, that he should not have feared the statements and objections of the people. Instead, his fear should have been for Allah alone. On account of this fear (for Allah), he should have made known to the people that which Allah had revealed to him that he would be married to Zainab (R.A) afterwards. (Safwatut Tafseer vol.12 pg. 63)
Allah further stated in the verse, ‘so when Zaid fulfilled his need from her, We married her to you’. This means that when Zaid had fulfilled his need as a husband with Zainab and then divorced her, Allah married her to the Prophet (S.A). While commenting on this verse, the commentators of the Holy Quran have stated that this verse shows that the Prophet’s intention to marry Zainab after Zaid had divorced her was in accordance to the revelation and decree of Allah. It was not on account of his own desire to have Zainab as his wife.
In the verse Allah stated to the Prophet (S.A), ‘We married her to you’. It means that Allah is saying, ‘(O Prophet), We have made her a wife for you’. While explaining this verse, the commentators have stated that this means that Allah Himself had solemnized this marriage and had given her (in marriage) to the Prophet (S.A). Allah then revealed to the Prophet (S.A) that he should go to Zainab and begin to live with her without any formal contract of Nikah, Wali (guardian), Mahr (dowry) and witnesses from among men. (Tafseer Ibn Katheer vol.3 pg. 491; Tafseer Al Qurtubi vol.14 pg. 170; Tafseer Ruhul Ma’ani vol.12 pg. 26; Safwatut Tafseer vol.12 pg. 63)
This was a special privilege given to the Prophet (S.A) by Allah, and no one has been granted this permission. It is with regards to this special honour, Zainab bint Jahsh (R.A) used to proudly highlight this virtue and say to the other wives of the Prophet (S.A), ‘Your guardians (and family members) have married you (to the Prophet S.A), but my Lord (Himself) has married me (to the Prophet S.A) from above the seven heavens’. (Bukhari)
Further in the verse, Allah mentions the hikmah (wisdom) in decreeing this marriage. He says, ‘so that there may not be any constraint (difficulty) on the believers with regard to the marriage of the wives of their adopted sons, when they (the adopted sons) have fulfilled their need from them’.
It means that through the occurrence of the marriage between the Prophet (S.A) and Zainab bint Jahsh (R.A), it will become clearly established that in the religion of Allah (Al Islam), there is no objection for one to marry the former wife of one’s adopted son. Hence, there will be no difficulty, embarrassment or objection upon the believers who wish to do so, and it will not be a sinful practice.
The verse then concludes by saying, ‘And Allah’s command must be fulfilled’. It means that the order of Allah to the Prophet (S.A) and the revelation sent to him with respect to the marriage with Zainab had to be fulfilled and accomplished, since it was already decreed by Allah.
Sura Al Ahzab continues in verse 38 and states:
38. There is no blame on the Prophet (S.A) in that which Allah has made legal for him. That has been Allah’s Way with those who have passed away of (the Prophets of) old. And the Command of Allah is a decree determined.
Here, Allah makes it clear to all people that there is no harm, sin or reproach upon the Prophet (S.A) in what he did, as allowed and instructed by Allah. None can rebuke him with respect to his marriages (and the marriage with Zainab bint Jahsh (R.A) since these were based on the allowances granted to him by Allah and not on his personal desires.
As mentioned by the great commentator Dhahak, the Jews criticized the Prophet (S.A) for his multiple marriages and accused him wrongfully. Upon this, Allah refuted them in this verse and also reminded them that the practice of the Prophet (S.A) with respect to marrying more than one wife was the same way of the previous prophets, and this was based on the allowance which Allah granted them. The verse stated, ‘that has been Allah’s way with those who passed away of (the prophets of) old’. It means that this was also practiced by the Prophets in the past, and Allah had increased for them in the allowance He has given. (Tafseer Al Bahrul Muheet vol.8 pg. 484 Darul Fikr Beirut 1992)
While commenting on this verse (which states, ‘There is no blame on the Prophet (S.A) in that which Allah has made legal for him’), Hafiz Ibn Katheer has mentioned, ‘It means that there is no blame upon him (the Prophet S.A) in what Allah has made halaal (lawful) for him and has ordered him to do, with regards to the marriage to Zainab (R.A) who was divorced by the adopted son of the Prophet (S.A), (Zaid bin Haritha). This (marriage, as well as marrying more than one wife) was the instruction of Allah to the Prophets before, and He would not order them to do anything which will bring harm to them’. (Tafseer Ibn Katheer vol.3 pg.492-Amjad Academy Lahore 1982)
Similarly, while commenting on this verse, the great exegete, Imam Qurtubi (A.R) writes, ‘This is an address from Allah to the whole Ummah. He has informed them that this [the marriage of the Prophet (S.A) to Zainab] and other similar practices were from the former ways of the Prophets. They practiced upon that which was allowed for them. Hence, Allah granted an allowance for the Prophet Muhammad (S.A) in marriage, what He had granted to the Prophets in the past. (Tafseer Al Qurtubi vol.14 pg. 173 Maktaba Rasheediya Queta Pakistan)
The verse ends by saying, ‘And the command of Allah is a decree determined’. It means that the decree of Allah has already been determined and it will certainly take place. No change will come to it nor shall it be altered. Hence, the Prophet’s marriage to Zainab (R.A), as well as his other marriages, were already decreed by Allah far before they occurred. Allah decrees whatever He wishes and His decrees are filled with wisdom. All things must follow the course of divine destiny and nothing strays from this order.
Having indicated to the great personalities of the Prophets and the allowances that Allah had given to them (regarding marriage), verse 39 goes further to make mention of these esteemed servants of Allah and their noble status in the sight of Allah. (Therefore, no one should entertain any ill feeling or evil thought in his heart regarding the marriages of the Prophets or any other practices that were done by them).