The Messenger of Allah ﷺ saw a person praying alone. He said: Is there any man who may do good with this (man) and pray along with him. (Using translation from Abū Dāʾūd 574)
أَنَّ النَّبِيَّ ﷺ أَبْصَرَ رَجُلًا يُصَلِّي وَحْدَهُ فَقَالَ أَلَا رَجُلٌ يَتَصَدَّقُ عَلَى هَذَا فَيُصَلِّي مَعَهُ؟