Is it permissible to place marble on the graves of Muslims, and is the calligrapher who writes on it sinful, and is it permissible to write verses from the distorted Gospel on the marble of Christian graves?

Writing on the grave and on the marker placed upon it is disliked (makrooh) by the majority of scholars, due to the Prophet's (peace be upon him) prohibition of it. This dislike intensifies if what is written is something from the Glorious Quran or if the marble is part of a structure built upon the grave, as building upon graves is forbidden.

If the writing is on the graves of non-Muslims, it is even more reprehensible, especially if it includes a commendation of them, because the graves of polytheists are a place of wrath and torment, and commending them contradicts the noble Hadith: "Wherever you pass by the grave of a polytheist, give him tidings of the Fire." This falls under cooperation in sin and aggression, which is forbidden in the Almighty's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." Similarly, it is not permissible to be hired to write distorted books for the People of the Book.