An interesting description of the Gospel from theTafsīr of al-Šahrastānī (d. 548/1153)
“The Gospel is a divine book, although it exists in four copies collected by four men from the apostles and innumerable difference are found therein...
It’s not God’s word or revelation in its entirety; rather, its like some of the Qur’an transmitted via the interpretation of exegetes inasmuch John, Mark, Luke, and Matthew cite it...