(2) باب مَيْلِ الرَّجُلِ إِلَى بَعْضِ نِسَائِهِ دُونَ بَعْضِ
It was narrated from Abu Hurairah that the Prophet said:
"Whoever has two wives and is inclined to favor one of them over the other, he will come on the Day of Resurrection with half of his body leaning."
Reference: Sunan an-Nasa'i 3942
In-book reference: Book 36, Hadith 4
English translation: Vol. 4, Book 36, Hadith 3394