Bhagavatapurana 5.14.39

5.14.39

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yad idaṃ yogānuśāsanaṃ na vā etad avarundhate yan nyasta-daṇḍā munaya upaśama-śīlā uparatātmānaḥ samavagacchanti //

39. (Generally) men do not take to this discipline of Yoga (which has come down from the glorious Brahman), which those sages fully realise who are firm in the habits of self-control and tranquility and have withdrawn their mind and heart from worldly things.