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
← Previous Hadith The Messenger of Allah (ﷺ) said: Let those who are sedate and prudent be near me, then those who are next to them (saying it tliree tinies), and beware of the tumult of the markets.

Sahih Muslim Book 4, Hadith 136 Next Hadith → The Messenger of Allah (ﷺ) said: Complete the rows, for I can see you behind my back.

Sahih Muslim Book 4, Hadith 138