Invocation to be recited after burying the dead
اللَّهُمَّ اغْفِرْ لَهُ الَّلهُمَّ ثَبِّتْهُ
164. Allaahum-maghfir lahu Allaahumma thabbithu.
O
Allah, forgive him. O Allah, strengthen him.
Reference: The Prophet
(SAW) used to stop after burying the dead and say to the people: "Ask
Allah to forgive your brother and pray for him to be strengthened, for
indeed he is now being questioned." Abu Dawud 3/315, and Al-Hakim 1/370
who graded it authentic and Ath-Thahabi agreed.