The Messenger of Allah (ﷺ) said: Complete the rows, for I can see you behind my back.
Sahih Muslim Book 4, Hadith 138
← Previous Hadith The Messenger of Allah (ﷺ) said: Straighten your rows. for the straightening of a row is a part of the perfection of prayer.

Sahih Muslim Book 4, Hadith 137 Next Hadith → This is what was transmitted to us by Abu Huraira from the Messenger of Allah (ﷺ) and, while making a mention of a few ahadith, said: (The Messengerof Allah directed us thus): Establish rows in prayer, for the making of a row (straight) is one of the merits of prayer.

Sahih Muslim Book 4, Hadith 139