Sahih Bukhari Volume 6, Book 65, Hadith 4890

حَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، حَدَّثَنَا أَبُو بَكْرٍ، عَنْ حُصَيْنٍ، عَنْ عَمْرِو بْنِ مَيْمُونٍ، قَالَ قَالَ عُمَرُ رضى الله عنه أُوصِي الْخَلِيفَةَ بِالْمُهَاجِرِينَ الأَوَّلِينَ أَنْ يَعْرِفَ لَهُمْ حَقَّهُمْ، وَأُوصِي الْخَلِيفَةَ بِالأَنْصَارِ الَّذِينَ تَبَوَّءُوا الدَّارَ وَالإِيمَانَ مِنْ قَبْلِ أَنْ يُهَاجِرَ النَّبِيُّ صلى الله عليه وسلم أَنْ يَقْبَلَ مِنْ مُحْسِنِهِمْ وَيَعْفُوَ عَنْ مُسِيئِهِمْ‏.‏

Narrated By 'Umar : I recommend that my successor should take care of and secure the rights of the early emigrants; and I also advise my successor to be kind to the Ansar who had homes (in Medina) and had adopted the Faith, before the Prophet migrated to them, and to accept the good from their good ones and excuse their wrong doers.