that the Messenger of Allah said: "Whoever has two wives and favors one of them over the other, he will come on the Day of Resurrection with one of his sides leaning." (Using translation from Ibn Mājah 1969)
قَالَ رَسُولُ اللهِ ﷺ مَنْ كَانَتْ لَهُ امْرَأَتَانِ يَمِيلُ مَعَ إِحْدَاهُمَا عَلَى الْأُخْرَى جَاءَ يَوْمَ الْقِيَامَةِ وَأَحَدُ شِقَّيْهِ سَاقِطٌ