Reference: ad-Durar an-Naadhirah fil-Fataaawa al-Mu’aasirah – Pages 676-677
Ibn Baaz – ad-Da’wah 1560, Jumaada al-Oolaa 1417AH
Question: Is there any evidence as to the legality of offering sincere words of religious advice at the graveside, since some of the people object to this. We [kindly] request you advise us, and may Allaah make great your reward?
Response: It has been established on the authority of the Prophet (sal-Allaahu ‘alayhi wa sallam) more than once that he offered sincere words of religious advice to the people at the graveside while they were awaiting the burial; and with that [example] it is known that offering sincere words of religious advice by the graveside is a legislated matter which the Prophet (sal-Allaahu ‘alayhi wa sallam) did, for that which it includes of the remembrance of death, Paradise and the [Hell] Fire and other than that from the affairs of the Hereafter and encouraging [the people] to prepare [themselves] for the meeting with Allaah. And Allaah is the Expounder of All success.