As the error was carried out because of 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. Together with Indra other gods have also granted him wishes: the God Agni granted Hanuman a https://hanumanhindutemplesaustralia.blogspot.com/2024/07/the-multifaceted-role-of-hanuman-mandir.html