As the error was done with the god Indra, he grants Hanuman a want that his physique would be as strong as Indra's Vajra, Which his Vajra also can not harm him. In addition to Indra other gods have also granted him wishes: the God Agni granted Hanuman a desire https://baglamukhi72727.shotblogs.com/not-known-factual-statements-about-hanuman-51010667