Title: 3 Rows at Funeral Prayer
Hadith: Narrated Malik ibn Hubayrah: The Prophet (peace_be_upon_him) said: If any Muslim dies and three rows of Muslims pray over him, it will assure him (of Paradise). When Malik considered those who accompanied a bier to be a few, he divided them into three rows in accordance with this tradition. [Abu Dawud Book 20, Hadith 3160]
