What is the ruling on teaching the deceased the word of tawhid (the oneness of Allah) and other things in his grave?

Question : May Allah reward you. It is said that we see many people, after burying the deceased, teaching him the deceased by saying: If you are asked, "Who is your Lord?" say, "My Lord is Allah." If you are asked, "Who is your Prophet?" say, "Muhammad." If you are asked, "What is your religion?" say, "Islam." Is there anything wrong with this action?

Answer : Yes, this is a reprehensible action, because the Prophet (peace and blessings be upon him) did not guide to it. Rather, he and did not teach him. This teaching is of no benefit whatsoever, because the deceased does not hear, as Allah the Exalted said: meaning he does not hear the teaching, otherwise he would hear the clatter of sandals, as we mentioned earlier. Also, he does not benefit from the teaching if he is not among the people of faith. And if he is among the people of faith, he has no need of the teaching. Listen, my son, we say: if he is a believer, he has no need of the timing, correct? Why? Because he will indicate it. And if he is a hypocrite, the teaching will not benefit him. Yes.