It was narrated from 'Aishah that the Prophet said:"No Muslim dies and a group of people whose number reaches one hundred offers the funeral prayer for him, interceding fro him, but their intercession for him will be accepted
Hadith No. 1992
Sunan an Nasai
Gradings:
Abu Ghuddah:
Sahih
Al-Albani:
Sahih
Zubair Ali Zai:
Sahih