In The Name of Allaah, The Most Merciful, The Bestower of Mercy.

Allaah [The Mighty and Majestic] said:

إِنَّ هَـٰذَا ٱلۡقُرۡءَانَ يَہۡدِى لِلَّتِى هِىَ أَقۡوَمُ

Verily, this Qur’an guides to that which is most just and right. [Surah Al-Israa. Aayah 9]

Imaam Muhammad Al-Ameen Bin Muhammad Al-Mukhtaar Ash-Shanqeeti [rahimahullaah] said:

And from the guidance of the Qur’aan to that which is most just and right is that it allows [a man to marry] four wives; but if the man fears that he cannot be just between them, then he is to restrict himself to one or those whom his right hand possesses, as Allaah (The Most High) stated:

وَإِنۡ خِفۡتُمۡ أَلَّا تُقۡسِطُواْ فِى ٱلۡيَتَـٰمَىٰ فَٱنكِحُواْ مَا طَابَ لَكُم مِّنَ ٱلنِّسَآءِ مَثۡنَىٰ وَثُلَـٰثَ وَرُبَـٰعَ‌ۖ فَإِنۡ خِفۡتُمۡ أَلَّا تَعۡدِلُواْ فَوَٲحِدَةً أَوۡ مَا مَلَكَتۡ أَيۡمَـٰنُكُمۡ‌ۚ ذَٲلِكَ أَدۡنَىٰٓ أَلَّا تَعُولُواْ

And if you fear that you shall not be able to deal justly with the orphan- girls, then marry (other) women of your choice, two or three, or four but if you fear that you shall not be able to deal justly (with them), then only one or (the captives and the slaves) that your right hands possess. [Surah An-Nisaa. Ayah:3]

No doubt the path that is the most just and right of paths is that which legitimizes for a man to have more than one wife due to the tangible affairs known to every sensible person. And from those affairs is that an individual woman menstruates, falls ill and contends with other hindrances that prevent her from fulfilling the more specific duties of marriage, whereas a man is readily prepared as a means to increasing the Ummah.

And from those affairs is that Allaah made it a common phenomenon that men are fewer in number than women in the various regions of the world and are more often exposed to the causes of death in all walks of life.  If a man were restricted to one wife, there would remain a great number of women deprived of marriage, so they [both men and women] will be strongly urged towards illegal sexual intercourse. Therefore, turning away from the guidance of the Qur’aan in this affair is one of the greatest causes of moral deprivation. It is (one of the greatest causes) of being lowered to the level of animals due to a lack of safeguarding chastity, preservation of nobility, good moral conduct and manners. So Glorified and Exalted is (Allaah) above all that evil they associate with Him, The All-Wise, Well-Acquainted with all things.  Allaah said:

الٓر‌ۚ كِتَـٰبٌ أُحۡكِمَتۡ ءَايَـٰتُهُ ۥ ثُمَّ فُصِّلَتۡ مِن لَّدُنۡ حَكِيمٍ خَبِيرٍ

‘(This is) a Book, the verses whereof are perfected (in every sphere of knowledge), and then explained in detail from One (Allaah), Who is All-Wise, Well-Acquainted (with all things)’ [Surah Hood. Ayah 1]

And from those affairs is that women are all readily prepared for marriage, whereas many men do not have the ability to fulfil the requirements of marriage due to poverty.  Those prepared for marriage amongst men are fewer than those amongst women. A woman is not hindered whereas a man is hindered by poverty and the ability to fulfil the requirements of marriage. If a man were restricted to one woman, many women prepared for marriage would have missed the opportunity for marriage. This would become a cause for loss of virtue, (a means to) depravation and moral decadence, and the opportunity to preserve the human race would be lost.

So if a man fears that he will not be able to deal justly between the wives, then it is incumbent upon him to restrict himself to one or to those whom his right hand possesses; because Allaah has stated:

إِنَّ ٱللَّهَ يَأۡمُرُ بِٱلۡعَدۡلِ وَٱلۡإِحۡسَـٰنِ

Verily, Allaah enjoins justice and kind treatment. [Surah Nahl. Aayah 90]

It is not permissible to incline towards giving preferential (treatment) with regards to the rights given by the divine law to each of the wives due to the saying of Allaah:

وَلَن تَسۡتَطِيعُوٓاْ أَن تَعۡدِلُواْ بَيۡنَ ٱلنِّسَآءِ وَلَوۡ حَرَصۡتُمۡ‌ۖ فَلَا تَمِيلُواْ ڪُلَّ ٱلۡمَيۡلِ فَتَذَرُوهَا كَٱلۡمُعَلَّقَةِ

You will never be able to do perfect justice between wives [regarding what is hidden in your heart as to who amongst them you love the most] even if it is your ardent desire, so do not incline too much to one of them [by giving her more of your time and provision] so as to leave the other hanging [i.e. neither divorced nor being given the rights due to her]. [Surah An-Nisaa. Aayah: 129]

As for the natural inclination towards loving some of them more than others, the human being is not able to prevent this because it is an emotional (affair) and the soul’s desire, but it is not something that is acted upon [i.e. leads to injustice]. This is what is intended by Allaah’s statement:

وَلَن تَسۡتَطِيعُوٓاْ أَن تَعۡدِلُواْ بَيۡنَ ٱلنِّسَآءِ

You will never be able to do perfect justice between wives. [Surah Nisaa; Ayah: 129]

The claim of some of the disbelievers amongst the enemies of Islaam is that to have more than one wife necessitates constant argumentation and disagreement which ends up in a life of misery, because whenever one of the wives is pleased the other is angered, so the two (wives) are always in displeasure and this is not wisdom.

This (above statement of some of the disbelievers) is a worthless statement whose worthlessness is clear to every sensible person. That is because argument and disagreement between individual members of a family does not cease, because it takes place between a man and his mother, father, children and his only wife. It is a common affair of no great concern alongside the overriding tremendous benefits of marrying more than one woman, such as safeguarding women, facilitating marriage for them and increasing the number of the Ummah so that they can stand firm against the enemies of Islaam in every affair; and an overriding tremendous benefit takes precedence over prevention of a small harm. [Ref 1]

Imaam Abdul Azeez Bin Baaz [rahimahullaah] said:

If a person marries (several women) in order to protect himself from (Zina) and to increase in numbers of children, then there is no problem in this. However, it should not be for the (purpose) of playing around. [Ref 2]

Finally: Who are those whom your right hand possess?

Listen to audio here by Shaikh Abdul Waahid Abu Khadeejah [hafidhahullaah]:

https://video.link/w/Qbaub

https://video.link/w/lUZtb

[Ref 1. An Excerpt from Tafseerul Qur’aan Bil Qur’aan Min Adwaa Al-Bayaan. Pages 428-429. Slightly paraphrased]

[Ref 2: Al-Hulalul Ibreeziyyah Min At-Taleeqaat Al-baaziyyah Alaa Saheeh Al-Bukhaaree Volume 4; Hadith Number:5069.  Footnote Number 3]