Mahabharata 3.189.12
व्यवहाररता वैश्या भविष्यन्ति कृते युगेषट्कर्मनिरता विप्राः क्षत्रिया रक्षणे रताः
vyavahāraratā vaiśyā bhaviṣyanti kṛte yugeṣaṭkarmaniratā viprāḥ kṣatriyā rakṣaṇe ratāḥ
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book