Fiqh-us-Sunnah Volume 4, Funerals and Dhikr, Fiqh 4.045A.

Section : A Larger Number is Much Preferred.

A larger gathering of people for the funeral prayer is preferable, as is reported by ‘Aishah who said: “The Prophet, peace be upon him, said, ‘If a Muslim dies and his funeral prayer is attended by a group of a hundred Muslims, and they all sincerely pray for his forgiveness, he is forgiven’.” This is narrated by Ahmad, Muslim, and Tirmizhi.

Ibn ‘Abbas reported: “I heard the Prophet, peace be upon him, saying: ‘If a Muslim dies and a group of forty people, who do not associate any one with Allah, pray for him, their prayer is accepted and he is forgiven.” This has been narrated by Ahmad, Muslim, and Abu Daw’ud.