Is reviling a Muslim by saying "You donkey" or "You stupid," and the like, with the addition of "may God elevate you," considered among the major sins?

Slandering a Muslim unjustly, whether with these words or others that cause him harm, is considered a major sin, based on the words of the Almighty: "And those who harm believing men and believing women for [something] other than what they have earned have certainly borne slander and obvious sin," and based on the words of the Prophet, peace and blessings be upon him: "Slandering a Muslim is فسوق (disobedience/impiety) and fighting him is disbelief." It is forbidden by the consensus of the Ummah, and its perpetrator is a fasiq (transgressor).