Verse 21

नासाद्यते ह्यनभ्यस्ता कांक्षतापि शठात्मना ।पुत्र शालिरिवाव्युप्ता तस्मादेनां समाहर

In plain words

Unpracticed, it is not attained, even by one who longs for it with a deceitful heart — like rice unsown, my son. Therefore take hold of it.