Sayyiduna Nu’man bin Bashir (may Allah be pleased with him) stated while delivering a sermon that the Prophet Muhammad (peace and blessings be upon him) used to straighten the rows, until he would make them like an arrow or a spear. On one occasion, he saw a man whose chest was protruding ahead of the row, so he said: O servants of Allah! Either you will straighten your rows, or Allah the Exalted will create discord among you.