Is it permissible for an abandoned child to file a lawsuit against someone who calls him "son of fornication" or "son of illicit relations"? And is the حد (prescribed punishment) to be carried out on the speaker, due to the lack of legitimate evidence to prove the accusation?

A foundling is a child whose parents are unknown. It is not necessarily the child of adultery; he may have been lost by his family or abandoned for other reasons. Whoever accuses a chaste foundling of being a child of adultery is subject to the Hadd (punishment) for false accusation, based on the Almighty's saying: (And those who accuse chaste women and then do not produce four witnesses - lash them with eighty lashes and do not accept their testimony ever after. And those are the defiantly disobedient) An-Nur/4. This applies to both men and women. The majority of scholars hold that whoever accuses the child of Mula'ana (mutual imprecation) of being a child of adultery shall be flogged with the Hadd for false accusation, and likewise, whoever accuses a foundling, because adultery has not been proven by lawful means. The preponderant view among the Malikis is that whoever says to a foundling, "O son of adultery," shall be subject to Hadd, due to the possibility that he was abandoned while being from a legitimate marriage.