Verse
नास्ति बुद्धिरयुक्तस्य न चायुक्तस्य भावना ।न चाभावयतः शान्तिर् अशान्तस्य कुतः सुखम् ॥
nāsti buddhirayuktasya na cāyuktasya bhāvanāna cābhāvayataḥ śāntir aśāntasya kutaḥ sukham
For one who is not in Yoga, there is no intelligence, no concentration of thought; for him without concentration there is no peace, and for the unpeaceful how can there be happiness?
Gītā 2·66