سورة الأنفال

Imam Baqir (peace be upon him): What is meant by the believers is the Ansar, that is the Aws and the Khazraj [the two prominent tribes of Medina].

Ali ibn Ibrahim (may Allah have mercy on him): فَإِنَّ حَسْبَکَ اللهُ هُوَ الَّذِی أَیَّدَکَ بِنَصْرِهِ وَ بِالْمُؤْمِنِینَ وَ أَلَّفَ بَیْنَ قُلُوبِهِمْ لَوْ أَنفَقْتَ مَا فِی الْأَرْضِ جَمِیعًا مَّا أَلَّفْتَ بَیْنَ قُلُوبِهِمْ وَ لَکِنَّ اللهَ أَلَّفَ بَیْنَهُمْ إِنَّهُ عَزِیزٌ حَکِیم [Indeed, Allah is sufficient for you. He is the One who supported you with His help and with the believers, and united their hearts. If you had spent all that is on the earth, you could not have united their hearts, but Allah united them; indeed He is Mighty, Wise] — the ones meant here are the Ansar (the people of Medina), and Allah brought their hearts into affection with one another [because between the two tribes of Aws and Khazraj in the days of jahiliyya there had been fierce warfare and long-standing enmity], and through them He aided His Prophet; as Allah has said: لَوْ أَنْفَقْتَ ما فِی الْأَرْضِ جَمِیعاً ما أَلَّفْتَ بَیْنَ قُلُوبِهِمْ وَ لکِنَّ اللهَ أَلَّفَ بَیْنَهُمْ [If you had spent all that is on the earth, you could not have united their hearts, but Allah united them]. So the ones whose hearts Allah brought together in affection are, specifically, the Ansar.

The Messenger (peace be upon him and his family): It is narrated from Imam Ali (peace be upon him): I heard the Messenger of Allah (peace be upon him and his family) say: "The believer is noble-natured and generous, and the transgressor is cunning and base. The best of the believers is the one who is on intimate terms with the believers, and there is no good in one who does not become intimate with others and with whom others do not become intimate." And [again] I heard the Messenger of Allah (peace be upon him and his family) say: "The worst of people is the one who bears enmity toward the believers and whose heart the believers' hearts also detest. Those who go about tale-bearing, who sow division between friends, and who look for people's faults — on the Day of Resurrection Allah will not look at them, nor will He purify them." Then he recited this verse: هُوَ الَّذِی أَیَّدَکَ بِنَصْرِهِ وَ بِالْمُؤْمِنِینَ وَ أَلَّفَ بَیْنَ قُلُوبِهِمْ [He is the One who supported you with His help and with the believers, and united their hearts].