Verse 30

फलवत्तागृहीतत्वे फलवत्तासुखप्रदम् ।कर्ता नो मन एवेह यत्कल्पयति तत्तथा

In plain words

When a thing is grasped as fruitful, it bestows the happiness of fruitfulness. Here our doer is manas alone: whatever it conceives, that becomes so.