The Prophet ﷺ said, "There is no deceased person over whom a community of Muslims numbering one hundred prays, interceding for him, except that their intercession for him is accepted."Salam said, Shuayb bin al-Habhab narrated this to us and said, "Anas bin Malik narrated it to me from the Prophet ﷺ."
حدثنا علي بن إسحاق أخبرنا عبد الله وعتاب قال حدثنا عبد الله أخبرنا سلام بن أبي مطيع عن أيوب عن أبي قلابة عن عبد الله رضيع عائشة
عن النبي ﷺ قال ما من ميت يصلي عليه أمة من المسلمين يبلغون أن يكونوا مائة فيشفعون له إلا شفعوا فيه قال سلام فحدثنا به شعيب بن الحبحاب فقال حدثني به أنس بن مالك عن النبي ﷺ
Its chain of transmission is sahih. Abdullah is Ibn Mubarak. Ayub is al-Sikhtiyani. Abdullah, the foster brother of Ayesha, is Ibn Yazid. All of them are trustworthy. The hadith was narrated by Muslim, 2/654, no. 947, in the Book of Funerals, chapter on one for whom a hundred people pray, by Abu Dawud, 3/515, no. 3166, in the Book of Funerals, chapter on the rows for the funeral prayer, and by Nasai, 4/75, no. 1991, in the Book of Funerals, chapter on the merit of one for whom a hundred people pray.