The ruling on raising the voice during the funeral procession and the adhan at the time of burial

Question:
The questioner Ahmad Salem: We have reviewed some of his questions, and this question remains for him. He says: When accompanying the funeral procession, O Shaykh, to the cemetery, they recite dhikr in a collective voice, such as: “La ilaha illa Allah, Muhammad rasul Allah” and the like. And when the deceased is placed in the grave, they perform the adhan and the iqamah. And after the burial, they instruct him, meaning they say: “O so-and-so, son of so-and-so, say: La ilaha illa Allah, say: My Lord is Allah, my religion is Islam, and my Prophet is Muhammad (peace and blessings be upon him).” What is your opinion regarding this practice?

Answer:
In the name of Allah, the Most Gracious, the Most Merciful. Praise be to Allah, and may Allah send prayers and blessings upon the Messenger of Allah, and upon his family and his Companions, and upon those who follow his guidance. As for what follows:
This entire practice is a bid'ah (religious innovation) and is not permissible. Raising voices with the funerals, or reciting “Wahdahu” (He is One), or “La ilaha illa Allah,” all of it is bid'ah. The Sunnah with funerals is to reflect, contemplate, be humble, remember death, and make du'a' (supplication) for the deceased. As for raising voices with dhikr or “Wahdahu,” all of this has no basis.
Likewise, the adhan in the grave, or the iqamah in the grave, is all bid'ah. And likewise, the instruction (talaqqin), saying “O so-and-so, remember what you came out of the world for,” is all bid'ah. The hadiths regarding instruction are all not authentic, not established from the Prophet (peace and blessings be upon him). So all of this is bid'ah. One does not instruct the deceased, and instruction does not benefit him. Only his prior deeds before death benefit him. As for after death, it does not benefit him. Likewise, the adhan in his grave, or the iqamah in his grave, or recitation, is all bid'ah and is not permissible. Yes.