Assalamu alaikum wa rahmatullahi wa barkatuh The Wisdoms of Islamic Polyandry as opposed to polygyny. The Holy Quran limits polygyny so that men are only allowed to marry plural wives if they are guardians of orphans, fearing being unable to protect them and also without any fear whatsoever of ever treating their wives unjustly. Polyandry on the other hand is allowed without limits according to An Nisa, as long as the wife allows herself to be one that her husband “right hands possess”.
First, we address the wisdom in allowing polyandry:
“…so, this is from the completeness of His blessing and Shari’ah, and is in accordance with His wisdom, mercy, and benefit for His servants. This is because one of the purposes of marriage is sexual intercourse and the fulfillment of one’s desire, and from the people are those who are overtaken by their desire, and are not satisfied with one. So, He allowed her a second, third, and fourth or a fifth one (since only the number of wives is restricted, not the number of husbands).
He then goes on to explain the wisdom in allowing unrestricted multiple spouses for the woman, in exclusion to the man:
“…this is from the completeness of the Wisdom of the Exalted Lord, and His goodness and mercy towards His servants, and His taking their interests into account, and He is Exalted above doing anything other than this, and His Shari’ah is far from coming with other than this. If it was allowed for the man to have more wives, the world would be ruined, and progeny would be lost, and the wives would end up killing each other, and a crisis would ensue, and the fitnah would become severe, and war would erupt. And how can the affair of the man remain firm when he has bickering partners? And how can the affair of these partners themselves remain firm? So, the coming of the Shari’ah with what it came with of opposition to this is from the greatest of proofs of the wisdom, mercy, and consideration of the Legisator.
So, if it is said: how can the interests of the woman be taken into account, with her being able to marry whom she wants, fulfill her desire, and move from one man to the next in accordance with her desires and needs – all while the needs of the man are just like her needs, and the desires of the man are just like her desires?
We answer: since it is the nature of the man to be concealed behind the walls and hidden in the depths of his home since we all know that man is lazy and arrogant, and his moods are cooler than that of the woman, and his outer and inner movements are less than her movements, and the woman has been given strength and intensity for intercourse that leads her desire more so than with the man, and she has been tested with what he has not been tested with, she is granted the choice of having multiple spouses that is not available to the man. This is from what Allah has set aside exclusively for the female, and has preferred for them over men, just as He has preferred for them compassion, being able to give birth to new life, emotional intelligence, endurance, etc. over men. Also, He has made women to be guardians over men, traversing about for the purpose of looking after their best interests, constantly on the lookout for means of sustaining them, encountering dangers, and exposing themselves to all types of hardships in the path of doing what is best for their husbands since women are more intelligent and less bent to stupidity and violence than men. So, the Exalted Lord is Thankful and Forbearing, and He thanks them for this, and has compensated them by instilling for them what He did not instill for their husbands.
And if you compare the fatigue, hardship, and efforts of the woman in fulfilling the interests of the men with what the men have to endure of jealousy, you would find that the woman’s share of having to endure this fatigue, hardship, and effort is much greater than what the men have to endure of jealousy…”
“As for the one who says that the desire of the man is even more than that of the woman, this is not the case. The driving force behind the desire is fervor (lit. heat). So, where is the fervor of the man in comparison to the fervor of the female? The man – because of his free time, slowness, and absence of what will keep him busy from the fulfillment of his desire – might be overtaken by his desire, and will not find that which would oppose it. Rather, it finds a heart and soul free from distraction. So, it is able to instill itself within him to the utmost, resulting in one assuming that his desire is multiple times that of the woman, and this is not the case.
And from that which proves this is that if a woman has intercourse with her husband, she can have intercourse with other men in the same time frame, and it is known that with each man, she displays desire and fervor that drives her to have intercourse. The man, on the other hand, if the woman fulfills her desire with him, he becomes exhausted, and does not seek to fulfill his desire with any additional woman within that time frame.
So, the wisdom of of the Decree, Legislation, Creation, and Command is implemented, and praise is for Allah.”
[‘I’lam al-Muwaqqi’in'; 2/64-66]