Marthad bin 'Abdullah Al-Yazni reported:
When Malik bin Hubairah (May Allah be pleased with him) offered a funeral prayer and found a small number of participants, he would divide them into three rows and would say that the Messenger of Allah (ﷺ) said, "If three rows of men offer funeral prayer over anyone, his entry into Jannah will become certain."[Abu Dawud and At- Tirmidhi].
App reference: Book 7, Hadith 40
Arabic/English book reference: Book 7, Hadith 934