As the mistake was completed with the god Indra, he grants Hanuman a desire that his system would be as strong as Indra's Vajra, Which his Vajra also can not harm him. Together with Indra other gods have also granted him wishes: the God Agni granted Hanuman a want that https://indiantemplesnearme.blogspot.com/2025/01/the-significance-of-hanuman-mandirs.html