As the error was finished because of the god Indra, he grants Hanuman a want that his overall body might be as robust as Indra's Vajra, and that his Vajra may not hurt him. In conjunction with Indra other gods have also granted him wishes: the God Agni granted Hanuman https://trentongigdt.blogitright.com/32893052/the-basic-principles-of-hanuman-mantra