As the mistake was done by the god Indra, he grants Hanuman a want that his overall body might be as powerful as Indra's Vajra, and that his Vajra could also not hurt him. In conjunction with Indra other gods have also granted him needs: the God Agni granted Hanuman https://hindutemplesouthaustralia.business.blog/2024/04/17/a-sanctuary-of-hindu-worship-and-community-spirit/