Bhagavatapurana 7.15.28

7.15.28

ṣaḍvargasaṃyamaikāntāḥ sarvā niyamacodanāḥ /
tadantā yadi no yogān āvaheyuḥ śramāvahāḥ //

28. All the rules restricting the conduct and habits of man have but one purpose to serve, viz., restraining of the six passions; and they would be only a source of mere labour and pain if they do not lead to contemplation and concentration.