وَعَنْهُ أَنَّ اَلنَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «إِذَا صَلَّيْتُمْ عَلَى اَلْمَيِّتِ فَأَخْلِصُوا لَهُ اَلدُّعَاءَ»
“If you offer the funeral prayer for a deceased person, supplicate Allah sincerely for him.” Related by Abu Dawud.
Bulugh al-Maram 675, Book 3, Funerals, Hadith 35. 1 min read