As the error was completed from the god Indra, he grants Hanuman a desire that his system will be as robust 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 wish https://hanumanmandiradelaide.blogspot.com/2024/07/discovering-divine-grace-of-lord.html