164
اللَّهُمَّ اغْفِرْ لَهُ، اللَّهُمَّ ثَبِّتْهُ
Allahummaghfir lah, Allahumma thabbithu
O Allah, forgive him. O Allah, make him firm.
When the Prophet ﷺ finished burying the dead, he would stand over the grave and say: "Ask forgiveness for your brother and ask that he be made firm, for he is now being questioned."
Source Sunan Abī Dāwūd 3221 Ṣaḥīḥ
Compiler cites Abū Dāwūd 3/315; al-Ḥākim graded it ṣaḥīḥ, with adh-Dhahabī agreeing (1/370)