Evidence that love of the Ansar and Ali (r.a.) is a part of faith and a sign thereof; Hating them is a sign of hypocrisy Sahih Muslim 76
Arabic hadith text
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا يَعْقُوبُ، - يَعْنِي ابْنَ عَبْدِ الرَّحْمَنِ الْقَارِيَّ - عَنْ سُهَيْلٍ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ "لاَ يُبْغِضُ الأَنْصَارَ رَجُلٌ يُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الآخِرِ "
Translation
It is reported on the authority of Abu Huraira that the Messenger of Allah (may peace and blessings be upon him) said
A person who believes in Allah and the Last Day never nurses a grudge against the Ansar.