It is narrated from Hazrat Abu Umamah (may Allah be pleased with him) that once the Noble Prophet (peace and blessings be upon him) saw a man praying alone, so he said: "Is there anyone who will give charity to him, that is, join him in prayer?" Upon hearing this, a man stood up and began to pray with him. The Noble Prophet (peace and blessings be upon him) said: "These two have become a congregation."
Hadith Referenceمسند احمد / مسند الأنصار رضي الله عنهم / 22189
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضعيف جدا، عبيدالله بن زحر ضعيف، وعلي بن يزيد واهي الحديث