When Hanuman, as an infant, attempted to capture and eat the sun (which he mistook for a ripe fruit), Indra, the king of gods, struck him with his thunderbolt (vajra). This blow injured Hanuman's jaw (hanu), leading to his name 'Hanuman' (one with a broken or prominent jaw). As a result of this incident, Indra later granted Hanuman the boon of immortality and invulnerability to all weapons.