It has reached us in the hadith of Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him), concerning the man who entered the mosque after the Messenger of Allah (peace and blessings be upon him) had already prayed, that he (peace and blessings be upon him) said: "Is there no one who will give charity to this man by praying with him?"
So a man stood up and prayed with him.
And from Imam al-Hasan al-Basri (may Allah have mercy on him), in a mursal report from the Prophet (peace and blessings be upon him) about this incident: "So Sayyiduna Abu Bakr (may Allah be pleased with him) stood up and prayed with him, although he had already prayed with the Prophet (peace and blessings be upon him)."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / Q3651