Dua 1
اَللّٰهُمَّ اغْفِرْ لِفُلَانٍ1 وَّارْفَعْ دَرَجَتَهٗ فِي الْمَهْدِيِّيْنَ وَاخْلُفْهُ فِيْ عَقِبِهٖ فِي الْغَابِرِيْنَ وَاغْفِرْ لَنَا وَلَهٗ يَا رَبَّ الْعَالَمِيْنَ وَافْسَحْ لَهٗ فِيْ قَبْرِهٖ وَنَوِّرْ لَهٗ فِيْهِ2
O Allah! Forgive so-and-so, raise his rank among the rightly guided, be his successor among those he leaves behind, and forgive us and him, O Lord of the worlds! Make his grave spacious for him and give him light in it.
In place of so-and-so, say the name of the person who has died.
Sahih Muslim, no. (920), the wording is his, Sunan Abi Dawud, no. (3118).