This is a hymn which occurs in the Valmiki Ramayana.

Valmiki Ramayana is well known. It was a scene in the Yudha Kanda during the final between Sri Rama and Ravana. The battle was in progress. Sri Rama had used all kinds of weapons and missiles against Ravana, but in vain. The power of Ravana seemed invincible. Sri Rama was tormented by fatigue, both mentally and physically. Then, there came a brief time of respite.

At this juncture, as the gods looked on the battle from the sky, the sage Agastya appeared in front of Rama. With the aim of rejuvenating Sri Rama and hastening the outcome of the battle, Sage Agasthya teaches to Sri Rama a prayer to the Sun-God, and disappeared soon after. Having received the prayer towards the Sun-God from Sage Agastya and upon reciting it Sri Rama became energized. He lifted his bow, prepared for the final confrontation and ultimately slayed Ravana in battle.

In this hymn of 31 slokas, the first 30 are set in the Anushtub meter. The various attributes and activities of the Sun-God are mentioned in verses 6 to15 and the verses 16 to 21 form the crux of the prayer. The listing of the benefits of recitation of the hymn called phalsruti is given initially in verses 3 to 5 and near the end in verses 25 to 27. It is said in the phalsruti that this hymn has the potency to vanquish all enemies, bestow victory and bless its chanter with unending auspiciousness, sound health and eradication of all miseries and sins. Agastya said to Sri Rama, “Oh Rama! During times of danger, in places of fear or uncertainty, whoever recites this hymn shall not fall into misery. Upon chanting this hymn thrice unto Lord Aditya with complete devotion, you shall attain victory and you shall defeat Ravana the very next instant.”

It is thus clear from what is stated therein that the hearing or chanting of this hymn would instill confidence inthe mind of the devotees, something which manifested almost instantaneously in Sri Rama.