اَللَّهُمَّ 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]

Allahum-maghfir lahu warhamhu, wa 'aafihi, wa'fu 'anhu, wa 'akrim nuzulahu, wa wassi' mudkhalahu, waghsilhu bilmaa'i waththalji walbarad, wa naqqihi minal-khataayaa kamaa naqqaytath-thawbal-'abyadha minad-danas, wa 'abdilhu daaran khayran min daarihi, wa 'ahlan khayran min 'ahlihi, wa zawjan khayran min zawjihi, wa 'adkhilhul-jannata, wa 'a'idhhu min 'adhaabil-qabr (wa 'adhaabin-naar)

O Allah, forgive him and have mercy on him and give him strength and pardon him. Be generous to him and cause his entrance to be wide and wash him with water and snow and hail. Cleanse him of his transgressions as white cloth is cleansed of stains. Give him an abode better than his home, and a family better than his family and a spouse better than his spouse. Take him into Paradise and protect him from the punishment of the grave [and from the punishment of Hell-fire]. Awf ibn Malik (RA) said, When the Messenger of Allah (ﷺ) performed the funeral prayer, I memorized this dua from him. Hearing this dua, I wished that the dead body would be me! (The dua is Mentioned above)

Reference: Muslim: 963