It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him): "The Prophet (peace and blessings be upon him) led the funeral prayer over a deceased person, and at that time there were seven men with him (peace and blessings be upon him). He (peace and blessings be upon him) made a row of three, a row of two and a row of two."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7754