Responsibility of the husband to be fair to all wives

وَإِنْ خِفْتُمْ أَلَّا تُقْسِطُوا۟ فِى ٱلْيَتَٰمَىٰ فَٱنكِحُوا۟ مَا طَابَ لَكُم مِّنَ ٱلنِّسَآءِ مَثْنَىٰ وَثُلَٰثَ وَرُبَٰعَ ۖ فَإِنْ خِفْتُمْ أَلَّا تَعْدِلُوا۟ فَوَٰحِدَةً أَوْ مَا مَلَكَتْ أَيْمَٰنُكُمْ ۚ ذَٰلِكَ أَدْنَىٰٓ أَلَّا تَعُولُوا۟

If ye fear that ye shall not be able to deal justly with the orphans, Marry women of your choice, Two or three or four; but if ye fear that ye shall not be able to deal justly (with them), then only one, or (a captive) that your right hands possess, that will be more suitable, to prevent you from doing injustice.

وَلَن تَسْتَطِيعُوٓا۟ أَن تَعْدِلُوا۟ بَيْنَ ٱلنِّسَآءِ وَلَوْ حَرَصْتُمْ ۖ فَلَا تَمِيلُوا۟ كُلَّ ٱلْمَيْلِ فَتَذَرُوهَا كَٱلْمُعَلَّقَةِ ۚ وَإِن تُصْلِحُوا۟ وَتَتَّقُوا۟ فَإِنَّ ٱللَّهَ كَانَ غَفُورًۭا رَّحِيمًۭا

Ye are never able to be fair and just as between women, even if it is your ardent desire: But turn not away (from a woman) altogether, so as to leave her (as it were) hanging (in the air). If ye come to a friendly understanding, and practise self-restraint, Allah is Oft-forgiving, Most Merciful.