Du'a for the deceased in the funeral prayer

اللَّهُمَّ اغْفِرْ لَهُ وَارْحَمْهُ، وَعَافِهِ وَاعْفُ عَنْهُ، وَأَكْرِمْ نُزُلَهُ، وَوَسِّعْ مُدْخَلَهُ، وَاغْسِلْهُ بِالْمَاءِ وَالثَّلْجِ وَالْبَرَدِ، وَنَقِّهِ مِنَ الْخَطَايَا كَمَا نَقَّيْتَ الثَّوْبَ الْأَبْيَضَ مِنَ الدَّنَسِ، وَأَبْدِلْهُ دَارًا خَيْرًا مِنْ دَارِهِ، وَأَهْلًا خَيْرًا مِنْ أَهْلِهِ، وَزَوْجًا خَيْرًا مِنْ زَوْجِهِ، وَأَدْخِلْهُ الْجَنَّةَ، وَأَعِذْهُ مِنْ عَذَابِ الْقَبْرِ وَعَذَابِ النَّارِ

Allahummaghfir lahu warhamhu, wa 'afihi wa'fu 'anhu, wa akrim nuzulahu, wa wassi' mudkhalahu, waghsilhu bil-ma'i wath-thalji wal-barad, wa naqqihi minal-khataya kama naqqaytath-thawbal-abyada minad-danas, wa abdilhu daran khayran min darihi, wa ahlan khayran min ahlihi, wa zawjan khayran min zawjihi, wa adkhilhul-jannata, wa a'idh-hu min 'adhabil-qabri wa 'adhabin-nar.

O Allah forgive and have mercy upon him, excuse him and pardon him and make honourable his reception. Expand his entry and cleanse him with water, snow and ice and purify him of sin as a white robe is purified of filth. Exchange his home for a better home, and his family for a better family, and his spouse for a better spouse. Admit him into Jannah and protect him from the punishment of the grave and the torment of the Hellfire.

Ṣaḥīḥ Muslim 963