Kaṭha Upaniṣad 6.10

6.10

yadā pañcāvatiṣṭhante jñānāni manasā saha /
buddhiś ca na viceṣṭati tām āhuḥ paramāṃ gatim //

10. When cease the five
[Sense-]knowledges, together with the mind (manas),

And the intellect (_buddhi_) stirs not— That, they say, is the highest course. 11. This they consider as Yoga— The firm holding back of the senses. Then one becomes undistracted. Yoga, truly, is the origin and the end.