Sahih Muslim 74
Sahih Muslim · Book 1: The Book of Faith · 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
It is narrated on the authority of Anas that the Apostle (may peace and blessings be upon him) said:
حَدَّثَنَا يَحْيَى بْنُ حَبِيبٍ الْحَارِثِيُّ ، حَدَّثَنَا خَالِدٌ، - يَعْنِي ابْنَ الْحَارِثِ - حَدَّثَنَا شُعْبَةُ ، عَنْ عَبْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ ، عَنْ أَنَسٍ ، عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ قَالَ " حُبُّ الأَنْصَارِ آيَةُ الإِيمَانِ وَبُغْضُهُمْ آيَةُ النِّفَاقِ " .
The love of the Ansar is the sign of faith and hatred against them is the sign of dissemblance.