As the mistake was done by the god Indra, he grants Hanuman a would like that his body can be as potent as Indra's Vajra, Which his Vajra might also not harm him. Together with Indra other gods have also granted him wishes: the God Agni granted Hanuman a desire https://andersonzhoub.canariblogs.com/little-known-facts-about-hanuman-51816714