Sunan Ibn Majah, Hadith 2320 ⓘ
It was narrated from Ibn 'Umar that the Messenger of Allah said: “Whoever takes the wrongdoer's side in a dispute or supports wrongdoing, he will remain subject to the wrath of Allah until he gives it up.”
حَدَّثَنَا مُحَمَّدُ بْنُ ثَعْلَبَةَ بْنِ سَوَاءٍ، حَدَّثَنِي عَمِّي، مُحَمَّدُ بْنُ سَوَاءٍ عَنْ حُسَيْنٍ الْمُعَلِّمِ، عَنْ مَطَرٍ الْوَرَّاقِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ أَعَانَ عَلَى خُصُومَةٍ بِظُلْمٍ - أَوْ يُعِينُ عَلَى ظُلْمٍ - لَمْ يَزَلْ فِي سَخَطِ اللَّهِ حَتَّى يَنْزِعَ " .
also referenced under: Book 13, Hadith 13 (In-Book) & Volume 3, Book 13, Hadith 2320 (DarusSalam)