As the error was finished from the god Indra, he grants Hanuman a wish that his physique can be as solid as Indra's Vajra, Which his Vajra could also not damage him. In conjunction with Indra other gods have also granted him needs: the God Agni granted Hanuman a want https://medium.com/@jameag789/a-spiritual-journey-through-sacred-spaces-in-australia-f3fdd7a34461