Bhagavad Gita: Chapter 18, Verse 29

बुद्धेर्भेदं धृतेश्चैव गुणतस्त्रिविधं शृणु |
प्रोच्यमानमशेषेण पृथक्त्वेन धनञ्जय || 29||

buddher bhedaṁ dhṛiteśh chaiva guṇatas tri-vidhaṁ śhṛiṇu
prochyamānam aśheṣheṇa pṛithaktvena dhanañjaya

buddheḥof intellect; bhedamthe distinctions; dhṛiteḥof determination; chaand; evacertainly; guṇataḥ tri-vidhamaccording to the three modes of material nature; śhṛiṇuhear; prochyamānamdescribed; aśheṣheṇain detail; pṛithaktvenadistinctly; dhanañjayaconqueror of wealth, Arjun

Translation

BG 18.29: Hear now, O Arjun, of the distinctions of intellect and determination, according to the three modes of material nature, as I describe them in detail.

Commentary

In the previous nine verses, Shree Krishna explained the constituents of work and showed that each of three constituents fall in three categories. Now he explains the two factors that impact the quality and quantity of work. They not only propel action but also control and direct it. These are the intellect and determination. Buddhi is the faculty of discrimination that distinguishes between right and wrong. Dhṛiti is the inner determination to persist in accomplishing the work undertaken, despite hardships and obstacles on the way. Both are of three kinds in accordance with the modes of nature. Shree Krishna now discusses both these faculties and their three-fold classifications.