Is it permissible to avoid and consider sinful one who curses a mother with the word "whore" and repeats that due to not greeting them with peace?

Describing a woman as a "prostitute" is an accusation of adultery (zina) against her, which is one of the major sins that necessitates the legal punishment (hadd) of eighty lashes for the accuser, if he does not produce four witnesses. His testimony will not be accepted, and he will be considered a dissolute person (fasiq). The implementation of this punishment is dependent on the ruler, and it is a right of the slandered person. There is no blame on the questioner for shunning the person who slandered his mother due to the heinousness of his act, especially if he is not a close relative. Similarly, it is permissible to shun a dissolute person who disregards God’s limits and whose punishment cannot be achieved.