As the error was accomplished because of the god Indra, he grants Hanuman a desire that his system would be as powerful as Indra's Vajra, Which his Vajra could also not damage him. Along with Indra other gods have also granted him wishes: the God Agni granted Hanuman a desire https://hanumanmandirsouthaustralia.movie.blog/2025/01/23/the-importance-of-hindu-temples-in-preserving-faith-and-culture/