|Chapter 2, Verse 67|

इन्द्रियाणां हि चरतां यन्मनोऽनुविधीयते।

तदस्य हरति प्रज्ञां वायुर्नावमिवाम्भसि।।2.67।।

ॐ

Transliteration / Meaning

indriyāṇāṁ hi charatāṁ yan mano ’nuvidhīyate
tadasya harati prajñāṁ vāyur nāvam ivāmbhasi

Translation

As a strong wind sweeps away a boat on the water, even one of the roaming senses on which the mind focuses can carry away a man's intelligence.

Purport by Srila Prabhupada

Unless all of the senses are engaged in the service of the Lord, even one of them engaged in sense gratification can deviate the devotee from the path of transcendental advancement. As mentioned in the life of Maharaja Ambarisha, all of the senses must be engaged in Krishna consciousness, for that is the correct technique for controlling the mind.