As the mistake was completed because of the god Indra, he grants Hanuman a desire that his human body might be as potent as Indra's Vajra, and that his Vajra may also not damage him. Coupled with Indra other gods have also granted him wishes: the God Agni granted Hanuman https://directory4search.com/listings13300793/the-fact-about-hanuman-that-no-one-is-suggesting