As the error was accomplished through the god Indra, he grants Hanuman a wish that his body could well be as solid as Indra's Vajra, Which his Vajra might also not damage him. Together with Indra other gods have also granted him needs: the God Agni granted Hanuman a want https://www.diigo.com/item/note/avyq4/mrqo?k=bcbd54afda6f5bd920d9265552372039