आत्मा नदी संयमतोयपूर्णा सत्यहृदा शीलतटा दयोर्मिः ।तत्रावगाहं कुरु पाण्डुपुत्र न वारिणा शुध्यति चान्तरात्मा ॥इति महाभारते ।'मानसं स्नानं विष्णुचिन्तनम्' इति विष्णुस्मृतौ ।
In plain words
Your own self is the river. Self-restraint is the water it runs with, truth its deep still pools, good conduct the banks that hold it, compassion the waves moving across it. Bathe there, son of Pāṇḍu — water never washes the inner self clean. So the Mahābhārata. And the Viṣṇu-smṛti: the bath taken in the mind is thinking of Viṣṇu.
Close to the Sanskrit
The self is a river, filled with the water of self-restraint, having truth for its deep pools, good conduct for its banks, compassion for its waves. In that take your plunge, son of Pāṇḍu; and the inner self is not made pure by water. — thus in the Mahābhārata. 'Mental bathing is the contemplation of Viṣṇu' — thus in the Viṣṇu-smṛti.