Narrated Uthman ibn Affan:
Whenever the Prophet (ﷺ) became free from burying the dead, he used to stay at him (i.e. his grave) and say: Seek forgiveness for your brother, and beg steadfastness for him, for he will be questioned now.
Abu Dawud said: The full name of the narrator Buhair is Buhair b. Raisan.