Is what is stated in the Gospel of Barnabas, chapter 54, verses 2-3, describing the Prophet as "sitting and not speaking because he would be as one distraught," considered an insult to the Prophet?

It is not permissible to peruse the Gospels that currently exist, nor to believe what is in them, due to the saying of the Hadith: "Do not believe the People of the Book, nor disbelieve them." Thus, whoever is not armed with religious knowledge and wishes to refute the people of falsehood, it is not permissible for him to engage with these books, because whatever truth is in them is found in the texts of the Book (Quran) and the Sunnah, and what is not mentioned in them is not permissible to believe or to examine. It has been established in authentic Ahadith that the Prophet, peace and blessings be upon him, will be the first to awaken on the Day of Resurrection, and that he is the one who will intercede for the people.