Āditya Hṛdayam, is a hymn associated with the Sun or Surya and was recited by the great sage Agastya to Rama on the battlefield before fighting with Ravana. This historic hymn starts at the beginning of the duel between Shri Rama with Ravana himself. Sage Agastya teaches Lord Rama, who is fatigued after the long battle with various fighters of Lanka, this procedure of worshiping Surya for strength to defeat the enemy. These verses belong to Yuddha Kanda (Book 6) Canto 107, in the Ramayana composed by Valmiki.