The Messenger of Allah ﷺ saw a man praying alone behind the row and ordered him to repeat his prayer.
حدثنا محمد بن جعفر حدثنا شعبة عن عمرو بن مرة قال سمعت هلال بن يساف يحدث عن عمرو بن راشد
أن رسول الله ﷺ رأى رجلا صلى وحده خلف الصف فأمره أن يعيد صلاته
Its isnad is sahih, and Amr bin Rashid is trustworthy, as noted many times before. The hadith was narrated with similar wording by Abu Dawud 1/439, no. 682, Tirmidhi 1/445, no. 230, Ibn Majah 1/321, no. 1004, Darimi 1/333, no. 1285, Ibn Abu Shayba 2/193, and Ibn Khuzayma 3/30, no. 1569.