The Messenger of Allah ﷺ saw a man praying alone behind the row, so he ordered him to repeat it. Sulayman bin Harb said, the prayer.
حدثنا سليمان بن حرب وحفص بن عمر قالا حدثنا شعبة عن عمرو بن مرة عن هلال بن يساف عن عمرو بن راشد
أن رسول الله ﷺ رأى رجلا يصلي خلف الصف وحده فأمره أن يعيد قال سليمان بن حرب الصلاة
Its chain of transmission is sahih. Tirmidhi narrated it in the chapters on prayer, in the section on what has been said about praying alone behind the row, hadith no. 231, from the hadith of Shubah with this wording, and he said, hasan, and Ibn Hibban graded it sahih, hadith no. 403. The hadith has other routes with Ibn Khuzayma, hadith no. 1569, and Ibn Hibban, hadith no. 401, and others besides them.