In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Question: What is the ruling on congregational supplication after the burial of the deceased?
Answer: Congregational supplication at the cemetery is not an established [act of worship that has been transmitted] from the Prophet [sallal laahu alayhi wasallam]. The Messenger [sallal laahu alayhi wasallam] said [i.e. after burial at the cemetery], ‘’Seek for forgiveness for your brother, and ask that he be made steadfast, for now he is being questioned”. [Abu Dawood, 3221]
Therefore, every person supplicates individually for his brother [i.e. the deceased]; as for doing so in congregation, then this is a bidah. The scholars even established that congregational supplication after the obligatory prayers is one of the innovations [in the religion], because if a deed is legislated to be performed individually but we perform it in a congregational manner, it would be tantamount to Bidah [in the religion]. This is the affair regarding bidah, for indeed there is no bidah except that it has a basis [in the religion]; whereas the true reality of sound adherence [to the authentic Sunnah of the Prophet] is that we perform an act of worship in the same manner it was performed by the Messenger [sallal laahu alayhi wasallam]. Our act of worship should be in conformity with that of the Messenger – in reality and in the manner he performed it; in conformity with what he intended and the manner in which he performed it. We cannot be true followers unless if the affair is like that.
The Messenger [sallal laahu alayhi wasallam] supplicated and commanded the companions to supplicate after the burial of one of his companions, so everyone supplicates individually by himself. Therefore, if we were to congregate behind an Imaam who supplicates and we say Aameen [i.e. after the burial at the cemetery], then indeed we have innovated in the religion and every newly invented matter [in the religion] is a Bidah; every bidah is misguidance and every act of misguidance [leads to the] hell fire. [Marhaban Yaa Taalibal Ilm. Page 362-363. Slightly paraphrased]