Bhagavad Geeta 6.21

Here is Bhagavad Gita, Chapter 6, Shloka 21 (6.21):

Sanskrit (Devanagari): सुखम् आत्यन्तिकं यत्तद् बुद्धिग्राह्यमतीन्द्रियम्। वेत्ति यत्र न चैवायं स्थितश्चलति तत्त्वतः।। 6.21 ।।

Transliteration: sukham ātyantikaṁ yat tad buddhi-grāhyam atīndriyam vetti yatra na caivāyaṁ sthitaś calati tattvataḥ

Meaning (English):

The yogi experiences supreme bliss, which is beyond the grasp of the senses and can only be understood through purified intellect (buddhi). Established in that state, one never deviates from the truth.