Verse 55

एवमभ्यागताभ्यासं मनोमत्तमतंगजम् ।निबध्य सर्वभावेन परं श्रेयोऽधिगम्यते

In plain words

Thus, when the mind -- a rutting elephant -- has been brought to abhyāsa and bound fast with one's whole being, the supreme good is attained.