Narrated Abu Bakr ibn Abi Shaybah, who said: Gundar narrated to us from Shu'bah. (Another chain:) Muhammad ibn al-Muthanna and Ibn Bashshar both said: Muhammad ibn Ja'far narrated to us, saying: Shu'bah narrated to us from 'Amr ibn Murrah, who said: I heard Salim ibn Abi al-Ja'd al-Ghatafani, who said: I heard al-Nu'man ibn Bashir, who said: I heard the Messenger of Allah (peace and blessings be upon him) say: "You must straighten your rows, or Allah will certainly cause discord among your hearts."