As the mistake was done by the god Indra, he grants Hanuman a want that his physique will be as strong as Indra's Vajra, and that his Vajra can also not hurt him. Along with Indra other gods have also granted him wishes: the God Agni granted Hanuman a desire https://laxmi70346.elbloglibre.com/37088937/the-2-minute-rule-for-hanuman