وَلَن تَسْتَطِيعُواْ أَن تَعْدِلُواْ بَيْنَ النِّسَاء وَلَوْ حَرَصْتُمْ
You will never be able to do perfect justice between wives even if it is your ardent desire,
Ibn Abbas, Ubaydah As-Salmani, Mujahid, Al-Hasan Al-Basri and Ad-Dahhak bin Muzahim stated,
means, O people! You will never be able to be perfectly just between wives in every respect. Even when one divides the nights justly between wives, there will still be various degrees concerning love, desire and sexual intimacy.
Imam Ahmad and the collectors of the Sunan recorded that Aishah said,
"The Messenger of Allah used to treat his wives equally and proclaim,
اللَّهُمَّ هَذَا قَسْمِي فِيمَا أَمْلِكُ فَلَ تَلُمْنِي فِيمَا تَمْلِكُ وَلَا أَمْلِك
O Allah! This is my division in what I own, so do not blame me for what You own and I do not own, (referring to his heart).
This was the wording that Abu Dawud collected, and its chain of narrators is Sahih.
Allah's statement,
فَلَ تَمِيلُواْ كُلَّ الْمَيْلِ
so do not incline too much to one of them,
means, when you like one of your wives more than others, do not exaggerate in treating her that way.
فَتَذَرُوهَا كَالْمُعَلَّقَةِ
so as to leave the other hanging.
referring to the other wives.
Ibn Abbas, Mujahid, Sa`id bin Jubayr, Al-Hasan, Ad-Dahhak, Ar-Rabi` bin Anas, As-Suddi and Muqatil bin Hayyan said that;
Mu`allaqah (hanging) means, "She is neither divorced nor married."
Abu Dawud At-Tayalisi recorded that Abu Hurayrah said that the Messenger of Allah said,
مَنْ كَانَتْ لَهُ امْرَأَتَانِ فَمَالَ إِلى إِحْدَاهُمَا جَاءَ يَوْمَ الْقِيَامَةِ وَأَحَدُ شِقَّيْهِ سَاقِط
Whoever has two wives and inclines to one of them (too much), will come on the Day of Resurrection with one of his sides dragging.
Allah's statement,
وَإِن تُصْلِحُواْ وَتَتَّقُواْ فَإِنَّ اللّهَ كَانَ غَفُورًا رَّحِيمًا
And if you do justice, and do all that is right and have Taqwa, then Allah is Ever Oft-Forgiving, Most Merciful.
The Ayah states;If you do justice and divide equally in what you have power over, while fearing Allah in all conditions, then Allah will forgive you the favoritism that you showed to some of your wives.
Allah then said,
وَإِن يَتَفَرَّقَا يُغْنِ اللّهُ كُلًّ مِّن سَعَتِهِ وَكَانَ اللّهُ وَاسِعًا حَكِيمًا