Is a person's saying to another, "Son of the whore..." considered an accusation of unchastity (qadhf) or an insult (sabb), or does it depend on the intention of the insulter?

Scholars have divided expressions of slander into explicit, allusive, and indirect. The local custom is referenced to determine whether the expression is intended to accuse someone of indecency or not. If it is commonly known to signify such an accusation, it is considered slander; otherwise, the speaker's intention is considered. The governing principles in this matter are common customary usages and circumstantial evidence. If both are absent, the person swears that they did not intend slander and is not subject to the prescribed punishment. If either is present, the punishment is applied. Slander has been counted among the seven destructive sins, and Allah has ordained a punishment of eighty lashes for the slanderer. It is mentioned in the Qur'an: "Indeed, those who accuse chaste, unaware [of the slander], believing women are cursed in this world and the Hereafter, and for them is a great punishment."