As the mistake was done because of the god Indra, he grants Hanuman a want that his overall body could well be as strong as Indra's Vajra, and that his Vajra can also not hurt him. In addition to Indra other gods have also granted him wishes: the God Agni https://kameroneqvdl.bloggosite.com/44264493/the-best-side-of-hanuman