As The error was accomplished via the god Indra, he grants Hanuman a wish that his entire body could be as solid as Indra's Vajra, Which his Vajra can also not harm him. Together with Indra other gods have also granted him wishes: the God Agni granted Hanuman a wish https://hanumanmandirsouthaustralia.sport.blog/2024/05/17/exploring-the-spiritual-oasis-hanuman-mandir-in-south-australia/