«كان إذا فرغ من دفن الميت وقف عليه فقال: استغفروا الله لأخيكم وسلوا له التثبيت فإنه الآن يسأل»
It was the practice of the Prophet (peace and blessings be upon him):
"When he (peace and blessings be upon him) had finished burying the deceased, he would stand at his grave and say: Seek forgiveness from Allah for your brother and ask for steadfastness for him, for he is being questioned right now."
Hadith Referenceصحیح الجامع الصغیر / حرف الكاف / 4760