"When Malik bin Hubairah performed Salat for a funeral and the people were few he would divide them into three groups (rows) then say: 'The Messenger of Allah said: "For whomever three rows perform Salat, then it is granted."
Jami` at-Tirmidhi Book 10, Hadith 64
← Previous Hadith "Ibn Abbas performed Salat for a funeral and he recited Fatihatil-Kitab. So I asked him about it and he said: 'It is from the Sunnah' or, 'From the completeness of the Sunnah.'"

Jami` at-Tirmidhi Book 10, Hadith 63 Next Hadith → The Prophet said: "No one among the Muslim dies, and Salat is performed for him by a community of Muslims reaching one hundred, and they intercede (supplicate) for him, except that their intercession for him is accepted." In his narration, 'Ali bin Hujr said: "One hundred or more than that."

Jami` at-Tirmidhi Book 10, Hadith 65