As the mistake was performed from the god Indra, he grants Hanuman a want that his system could be as solid as Indra's Vajra, Which his Vajra may also not damage him. In conjunction with Indra other gods have also granted him wishes: the God Agni granted Hanuman a wish https://magnetdirectory.com/listings13287156/the-smart-trick-of-hanuman-that-no-one-is-discussing