4:129
وَ لَن تَسْتَطِيعُ وٓا۟ أَن تَعْدِلُ وا۟ بَيْنَ ٱل نِّسَآءِ وَ لَوْ حَرَصْ تُمْ فَ لَا تَمِيلُ وا۟ كُلَّ ٱلْ مَيْلِ فَ تَذَرُ و هَا كَ ٱلْ مُعَلَّقَةِ وَ إِن تُصْلِحُ وا۟ وَ تَتَّقُ وا۟ فَ إِنَّ ٱللَّهَ كَانَ غَفُورًا رَّحِيمًا
And you will never be able to be equal [in feeling] between wives, even if you should strive [to do so]. So do not incline completely [toward one] and leave another hanging. And if you amend [your affairs] and fear Allah - then indeed, Allah is ever Forgiving and Merciful.