ENOfficial
‘A’isha reported the Prophet (ﷺ) as saying, "If a company of Muslims to the number of a hundred pray over a dead person, all of them interceding for him, their intercession for him will be accepted.” Muslim transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: " مَا مِنْ مَيِّتٍ تُصَلِّي عَلَيْهِ أُمَّةٌ مِنَ الْمُسْلِمِينَ يَبْلُغُونَ مِائَةً كُلُّهُمْ يَشْفَعُونَ لَهُ: إِلَّا شفعوا فِيهِ ". رَوَاهُ مُسلم
sunnah.com