Sunan an Nasai
810
Hasan Sahih+2

It was narrated that An-Numan bin Bashir said:"The Messenger of Allah (ﷺ) used to straighten the rows like shaft of an arrow is straightened before the head is attached to it. He saw a man whose chest was sticking out from the row. I saw the Messenger of Allah (ﷺ) say: 'Make your rows straight or Allah will cause your faces to be deformed

Hasan SahihAbu Ghuddah
Hasan SahihAl-Albani