As the error was completed by the god Indra, he grants Hanuman a desire that his physique can be as robust as Indra's Vajra, Which his Vajra also can not hurt him. In conjunction with Indra other gods have also granted him wishes: the God Agni granted Hanuman a desire https://sadhna28518.blogkoo.com/the-smart-trick-of-hanuman-that-no-one-is-discussing-56330075