اللَّهُمَّ اغْفِرْ لِفُلانٍ (باسْمِهِ)، وَارْفَعْ دَرَجَتَهُ في المَهْدِيِّيْنَ، وَاخْلُفْهُ في عَقِبِهِ في الغَابِرِيْنَ، وَاغْفِرْ لَنَا وَلَهُ يَا رَبَّ العَالَمِيْنَ، وَافْسَحْ لَهُ في قَبْرِهِ وَنَوِّرْ لَهُ فِيْهِ

O Allāh, forgive (mention the name of the deceased) and raise his rank among the rightly guided, and be a successor to whom he has left behind, and forgive us and him, O Lord of the worlds. Make spacious his grave and illuminate it for him.

Reference: O Allāh, forgive (mention the name of the deceased) and raise his rank among the rightly guided, and be a successor to whom he has left behind, and forgive us and him, O Lord of the worlds. Make spacious his grave and illuminate it for him. Muslim (#920, 2/634).