The Messenger of Allah ﷺ said, "Straighten your rows, for by Allah, I see you from behind me just as I see you from in front of me."
حدثنا عفان حدثنا حماد عن ثابت
أن رسول الله ﷺ قال استووا فوالله إني لأراكم من خلفي كما أراكم من بين يدي
Its isnad is sahih. It was mentioned previously at 13904.