Mbh 13.108.2a

"'Bhishma said, "Without doubt, all Tirthas are possessed of merit. Listen, however, with attention to me as I tell thee what the Tirtha, the cleanser, is of men endued with wisdom. Adhering to eternal Truth, one should bathe in the Tirtha called Manasa, which is unfathomable (for its depth), stainless, and pure, and which has Truth for its waters and the understanding for its lake.[502] The fruits in the form of cleansing, that one acquires by bathing in that Tirtha, are freedom from cupidity, sincerity, truthfulness, mildness (of behaviour), compassion, abstention from injuring any creature, self-restraint, and tranquillity. Those men that are freed from attachments, that are divested of pride, that transcend all pairs of opposites (such as pleasure and pain, praise and blame, heat and cold, etc.), that have no spouses and children and houses and gardens, etc., that are endued with purity, and that subsist upon the alms given to them by others, are regarded as Tirthas. He who is acquainted with the truths of all things and who is freed from the idea of meum, is said to be the highest Tirtha.[503] In searching the indications of purity, the gaze should ever be directed towards these attributes (so that where these are present, thou mayst take purity to be present, and where these are not, purity also should be concluded to be not). Those persons from whose souls the attributes of Sattwa and Rajas and Tamas have been washed off, they who, regardless of (external) purity and impurity pursue the ends they have proposed to themselves, they who have renounced everything, they who are possessed of omniscience and endued with universal sight, and they who are of pure conduct, are regarded as Tirthas possessing the power of cleansing. That man whose limbs only are wet with water is not regarded as one that is washed. He, on the other hand, is regarded as washed who has washed himself by self-denial. Even such a person is said to be pure both inwardly and outwardly.