As the error was finished with the god Indra, he grants Hanuman a desire that his human body might be as sturdy as Indra's Vajra, Which his Vajra can also not hurt him. Together with Indra other gods have also granted him needs: the God Agni granted Hanuman a desire https://www.diigo.com/item/note/avyq4/mrqo?k=bcbd54afda6f5bd920d9265552372039