As the error was finished because of the god Indra, he grants Hanuman a wish that his entire body might be as powerful as Indra's Vajra, and that his Vajra might also not damage him. Along with Indra other gods have also granted him wishes: the God Agni granted Hanuman https://thedirectoryblog.com/listings13333450/not-known-factual-statements-about-hanuman