Verse
इति गुह्यतमं शास्त्रम् इदमुक्तं मयाऽनघ ।एतत्बुद्ध्वा बुद्धिमान्स्यात् कृतकृत्यश्च भारत ॥
Thus by Me the most secret Shastra (the supreme teaching and science) has been told, O sinless one. Absolutely to know it is to be perfected in understanding and successful in the supreme sense, O Bharata.
Gītā 15·20