As the mistake was performed with the god Indra, he grants Hanuman a desire that his system would be as robust as Indra's Vajra, and that his Vajra can also not hurt him. Along with Indra other gods have also granted him needs: the God Agni granted Hanuman a want https://hanuman-shabhar-mantra42637.isblog.net/the-5-second-trick-for-hanuman-54113218