اللَّهُمَّ اغْفِرْ لَهُ وَارْحَمْهُ وَعَافِهِ وَاعْفُ عَنْهُ وَأَكْرِمْ نُزُلَهُ وَوَسِّعْ مُدْخَلَهُ وَاغْسِلْهُ بِالْمَاءِ وَالثَّلْجِ وَالْبَرَدِ وَنَقِّهِ مِنَ الْخَطَايَا كَمَا يُنَقَّى الثَّوْبُ الْأَبْيَضُ مِنَ الدَّنَسِ
Transliteration
Allahummaghfir lahu warhamhu wa 'afihi wa'fu 'anhu wa akrim nuzulahu wa wassi' mudkhalahu waghsilhu bil-ma'i wath-thalji wal-baradi wa naqqihi minal-khataya kama yunaqqath-thawbul-abyadu minad-danas
English meaning
O Allah, forgive him, have mercy on him, give him wellness and pardon him, make honorable his reception, make wide his entrance, and wash him with water, snow and hail. Purify him from sin as a white garment is purified from filth.
When is it recited?
Recited after the third takbir in the funeral prayer.
Source
Muslim, Jana'iz 26, 963