A all-powerful mantra for destroying enemies. According to Ramayana Yudhakanda Sarga 107, sometime during the war with Ravana, Rama became immersed deep in thought and was immobilised. Ravana chose this moment to advance. As the devas watched from above to see how the battle would unfold, Agastya approached Rama and taught him the adityahridaya mantra. Having grasped the mantra, Rama resumed battle and defeated Ravana.