Mahabharata 3.198.61

शिष्टाचारे मनः कृत्वा प्रतिष्ठाप्य च सर्वशःयामयं लभते तुष्टिं सा न शक्या ह्यतोऽन्यथा

śiṣṭācāre manaḥ kṛtvā pratiṣṭhāpya ca sarvaśaḥyāmayaṃ labhate tuṣṭiṃ sā na śakyā hyato'nyathā

Our plain-language meaning of this verse is waiting for scholar review.