As the error was carried out because of the god Indra, he grants Hanuman a wish that his body could well be as powerful as Indra's Vajra, and that his Vajra may not harm him. In conjunction with Indra other gods have also granted him needs: the God Agni granted https://hindutempleinadelaide.wordpress.com/2024/08/08/the-construction-of-hanuman-mandir-a-communitys-spiritual-journey/