As The error was performed by the god Indra, he grants Hanuman a desire that his body can be as sturdy as Indra's Vajra, Which his Vajra could also not harm him. As well as Indra other gods have also granted him needs: the God Agni granted Hanuman a want https://www.tumblr.com/hanumanmandiradelaide/792814428360933376/hanuman-ji-mandir-adelaide-blessings-devotion?source=share