If a company of Muslims numbering one hundred pray over a dead person, all of them interceding for him, their intercession for him will be accepted.
Sahih Muslim Book 11, Hadith 76
← Previous Hadith " The Apostle of Allah (ﷺ) was asked about qirat, and he said: It is equivalent to Uhud."

Sahih Muslim Book 11, Hadith 75 Next Hadith → So I went out and I informed him about the people who had gathered there. He (Ibn 'Abbas) said: Do you think they are forty? He (Kuraib) said: Yes. Ibn 'Abbas then said to them: Bring him (the dead body) out for I have heard Allah's Messenger (ﷺ) as saying: If any Muslim dies and forty men who associate nothing with Allah stand over his prayer (they offer prayer over him), Allah will accept them as intercessors for him.

Sahih Muslim Book 11, Hadith 77