“A son of ‘Abdullah bin ‘Abbas died, and he said to me:
‘O
Kuraib! Get up and see if anyone has assembled (to pray) for my
son.’
I said: ‘Yes.’ He said: ‘Woe to you, how many do you
see? Forty?’ I
said: ‘No, rather there are more.’ He said:
‘Take my son out, for I
bear witness that I hear the Messenger of
Allah (ﷺ) say: “No (group
of) forty believers intercede for a
believer, but Allah will accept
their intercession.”
Sunan Ibn Majah Book 6, Hadith 57