You will never be able to be just to your wives, even if you are eager; yet do not turn altogether away, so that you leave her like one suspended. If you set things right, and fear, surely God is ever Forgiving, Merciful.
[This] means when your concern is for yourself in your affairs, the state of your union together is overturned, and what was sound becomes ruined. But when you have made God your concern in your affairs, the balance of your life together will be restored and at that time will be cleared of turmoil.
It is said that if God has decreed deficiency in intellect as someone's state, it will not be possible for you to set that deficiency right by your competence.
Yet do not turn altogether away: [This] means do not deviate from the clear path of the command. Stop where you have been told to stop and do what you have been commanded to do.
So that you leave her like one suspended: [This] means that when you prevent them from being with someone other than you, even as you cut them off from any share of you, you harm [them] in two ways, for there is nothing to be had from you and there [is] no way for them to be with someone else. This harm is very grave.
The allusion in this [verse] is that when the path to your share in worldly things is blocked, He (سبحانه) enables you to witness His reality to you and find His kindness. Surely whoever's annihilation is in God (fa-inna man kāna fī Allāh talafuhu), the Real is his substitute (fa-l-ḥaqq subḥānahu khalafuhu). If you set things right between you and other created beings (wa-in tuṣliḥū mā baynakum wa-bayna al-khalq), and put your trust in what is between you and the Real (wa-tathiqū fīmā baynakum wa-bayna al-ḥaqq), surely God is ever forgiving of your failings (fa-inna Allāha ghafūrun li-ʿuyūbikum), merciful in pardoning your sins (raḥīmun bi-l-ʿafwi ʿan dhunūbikum).