It is natural for human beings to commit sins, either knowingly or unknowingly. Very often they realise their mistakes and even repent for them. As knowers of human psychology, the ṛṣis (sages) of yore have prescribed certain religio-spiritual rituals that help in the eradication of sins.
The Aghamarṣaṇasūkta is one such Vedic hymn (of prayer) prescribed for this purpose.
It forms an integral part of the Mahānārāyaṇa Upaniṣad (Anuvāka 1, mantras 55-70).
Water is a great purifying agent and should therefore be considered as an aspect of the Divine. Varuṇa is the presiding deity of water.
This sūkta has to be chanted before taking bath in a river or lake or tank.
The gist of the whole sūkta can be stated as follows:
I take refuge in Varuṇa. Pardon me for having accepted gifts from unworthy persons.
May Indra, Varuṇa, Bṛhaspati and Savitā destroy the sins committed by me. My salutations to them.
Through the power of this mantra, let all the impurities in this water (where I am to bathe now) be destroyed. May Varuṇa purify me.
I invite the seven sacred rivers—Gaṅgā, Yamunā, Sarasvatī, Godāvarī, Narmadā, Sindhū and Kaverī—to be present here in this water.
May Varuṇa, capable of effacing all sins, purify all the beings dwelling on the earth, in the atmospheric region and in heaven. Similarly may the Vasus also purify us.
I am the Supreme Light which projected itself as the universe. I am the same light that shines as the inmost essence of all that exists.
Varuṇa, the regent of waters and effacer of sins, absolves the sinners of all types.
Though I am the ground of sins and am made to weep, wise men can favour me by destroying my sins.
The Supreme Lord is infinite like the limitless ocean. He dwells in the hearts of devotees. He delights the individual souls by guiding them and offering the fruits of their action.