Mahabharata 12.189.13

विषयेभ्यो नमस्कुर्याद्विषयान्न च भावयेत्साम्यमुत्पाद्य मनसो मनस्येव मनो दधत्

viṣayebhyo namaskuryādviṣayānna ca bhāvayetsāmyamutpādya manaso manasyeva mano dadhat

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