The Messenger (May Allāh praise him and Peace be upon him) forbade that one man pray behind the row. It was narrated from Wābiṣah that the Messenger (May Allāh praise him and Peace be upon him) saw a man praying alone behind the row and told him to repeat his prayer. [Ṣaḥīḥ Sunan Abī Dāwūd 633].