As the error was carried out through the god Indra, he grants Hanuman a want that his human body can be as solid as Indra's Vajra, Which his Vajra might also not damage him. In conjunction with Indra other gods have also granted him needs: the God Agni granted Hanuman https://www.evernote.com/shard/s419/sh/6f1adc7c-5a1b-117c-f079-875254cd9fe6/v2a02NcvHBBzK4l7fflggfofxuT820h-g9EkHLyqWTxcnvnHUaapSFFn8g