Chapter 2: Contents of the Gītā Summarized
indriyanam hi caratam
yan mano 'nuvidhiyate
tad asya harati prajnam
vayur navam ivambhasi
indriyāṇām—of the senses; hi—certainly; caratām—while herding over; yat—that; manaḥ—mind; anuvidhīyate—becomes constantly engaged; tat—that; asya—his; harati—takes away; prajñām—intelligence; vāyuḥ—wind; nāvam—a boat; iva—like; ambhasi—on the water.
As a boat on the water is swept away by a strong wind, even one of the senses on which the mind focuses can carry away a man's intelligence.
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 Mahārāja Ambarīṣa, all of the senses must be engaged in Kṛṣṇa consciousness, for that is the correct technique for controlling the mind.