Sahih Muslim
436.01

Nu'man b. Bashir reported:I heard the Messenger of Allah (ﷺ) say: Straighten your rows, or Allah would create dissension amongst you

436.02

Nu'man b. Bashir reported:The Messenger of Allah (may peace-be upon him) used to straighten our rows as it lie were straightening an arrow with their help until be saw that we had learnt it from him. One day he came out, stood up (for prayer) and was about to say: Allah is the Greatest, when he saw a man, whose chest was bulging out from the row, so he said: Servants of Allah, you hint straighten your rows or Allah would create dissension amongst you

436.03

Abu 'Awana reported this hadith with the same chain of transmitters