النساۤء — An-Nisa' Ayat 129
وَلَنْ تَسْتَطِيْعُوْٓا اَنْ تَعْدِلُوْا بَيْنَ النِّسَاۤءِ وَلَوْ حَرَصْتُمْ فَلَا تَمِيْلُوْا كُلَّ الْمَيْلِ فَتَذَرُوْهَا كَالْمُعَلَّقَةِ ۗوَاِنْ تُصْلِحُوْا وَتَتَّقُوْا فَاِنَّ اللّٰهَ كَانَ غَفُوْرًا رَّحِيْمًا
Wa lan tastaṭī‘ū an ta‘dilū bainan-nisā'i wa lau ḥaraṣtum falā tamīlū kullal-maili fa tażarūhā kal-mu‘allaqah(ti), wa in tuṣliḥū wa tattaqū fa innallāha kāna gafūrar raḥīmā(n).
"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."