BG 3.7

But those karm yogis who control their knowledge senses with the mind, O Arjun, and engage the working senses in working without attachment, are certainly superior.

BG 3.41

Therefore, O best of the Bharatas, in the very beginning bring the senses under control and slay this enemy called desire, which is the embodiment of sin and destroys knowledge and realization.

BG 6.26

Whenever and wherever the restless and unsteady mind wanders, one should bring it back and continually focus it on God.

BG 18.51-53

One becomes fit to attain Brahman when he or she possesses a purified intellect and firmly restrains the senses, abandoning sound and other objects of the senses, casting aside attraction and aversion. Such a person relishes solitude, eats lightly, controls body, mind, and speech, is ever engaged in meditation, and practices dispassion. Free from egotism, violence, arrogance, desire, possessiveness of property, and selfishness, such a person, situated in tranquility, is fit for union with Brahman (i.e., realization of the Absolute Truth as Brahman).