Verse 18

तावद्भवमहाम्भोधौ जनस्तृणवदुह्यते ।विचारतटविश्रान्तिमेति यावन्न चेतसा

In plain words

So long a person is carried along like a blade of grass in the great ocean of becoming, until, through the mind, he comes to rest on the shore of inquiry.