As the error was performed because of the god Indra, he grants Hanuman a desire that his overall body would be as robust as Indra's Vajra, and that his Vajra could also not hurt him. Along with Indra other gods have also granted him wishes: the God Agni granted Hanuman https://richardd442tdq5.blogs100.com/37556405/the-smart-trick-of-hanuman-that-nobody-is-discussing