What is the ruling on calling a Muslim who committed a major sin - and repented from it - a dog or a donkey?

The sacred texts have warned against insulting and reviling, and have commanded the Muslim to guard his tongue. Therefore, it is impermissible to describe a Muslim with reprehensible attributes, because "reviling a Muslim is a transgression" and "the believer is not a slanderer, nor a curser, nor an obscene speaker, nor an evil talker." And whoever repents from a sin, Allah accepts his repentance, so it is not permissible to describe him with a sin from which he has already repented.