It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that a man came who had missed the prayer, and the Messenger of Allah (peace and blessings be upon him) said to him: "Pray." Then he said: "Is there no one who will give charity to this man and pray with him?" So a man stood up and prayed with him, and the Messenger of Allah (peace and blessings be upon him) said: "This too is a congregation."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7943