Verse 35

सर्वेषामुत्तमस्थानां सर्वासां चिरसंपदाम् ।स्वमनोनिग्रहो भूमिर्भूमिः सस्यश्रियामिव

In plain words

Mastery over one's own mind is the ground of all the highest states, of all lasting fortunes -- the ground, as the ground is of the splendour of crops.