What is the ruling regarding a son, angry and quarreling with his mother, saying to her: "Even if God Himself descended, I would not be pleased," expressing his desire for her not to be pleased?

This word is ugly and reprehensible, and it shows ill manners towards Allah Almighty. It is not befitting for a Muslim, especially if he addresses his mother with it, as that could hurt her and lead to disobedience (disrespecting parents). The one who uttered it must repent, honor his mother, and seek her satisfaction. It appears that he does not disbelieve by uttering this word unless he said it out of contempt and mockery of Allah. It is obligatory for a Muslim to guard his tongue from evil speech, because the tongue can lead its owner to destruction.