The sins that one commits during the day by one's senses or the mind are all washed off before evening by reciting a portion of the Mahabharata.
अह्ना यदेनः कुरुते इन्द्रियैर्मनसापि वा। महाभारतमाख्याय पश्चात् संध्यां प्रमुच्यते॥