As the mistake was completed because of the god Indra, he grants Hanuman a want that his overall body would be as solid as Indra's Vajra, and that his Vajra could also not harm him. Together with Indra other gods have also granted him needs: the God Agni granted Hanuman https://lukasndoyb.buyoutblog.com/36948586/a-simple-key-for-hanuman-unveiled