when someone is indulging in a mistake, the islamic principle is far from their minds and is lost in the clamour of the moment. in such cases reiterating the islamic principle and announcing it loudly can be an effective way of stopping the person in his tracks and making him wake up from the stupor that has overtaken him. when we look at what happened between the muhaajiroon and ansaar, because of the flames of fitnah stirred up by the munaafiqoon, we will see an example of how the prophet (peace and blessings of allaah be upon him) used this tactic. al-bukhaari (may allaah have mercy on him) reported in his saheeh that jaabir (may allaah be pleased with him) said:
“we went out on a military campaign with the messenger of allaah (peace and blessings of allaah be upon him), and some of the muhaajiroon went with him too, and they were very many. among the muhaajiroon was a man who was very playful (a joker). he shoved an ansaari (in jest), and the ansaari got very angry with him and called others to support him, saying, ‘o ansaar!’ the muhaajir called out, ‘o muhaajireen!’ the prophet (peace and blessings of allaah be upon him) came out and said, ‘what is this call of the people of jaahiliyyah all about?’ then he said, ‘what is the matter with him?’ he was told about how the muhaajir had shoved the ansaari in jest. the prophet (peace and blessings of allaah be upon him) said, ‘leave it, for it (tribalism) is evil.’ ” (al-fath, 3518).
according to a report narrated by muslim, he said:
“let a man help his brother whether he is an wrongdoer or the victim of wrongdoing. if he is a wrongdoer, he should stop him, and if he is the victim of wrongdoing, he should come to his aid.” (saheeh muslim, no. 2584).