चञ्चलं हि मन: कृष्ण प्रमाथि बलवद्दृढम् ।
तस्याहं निग्रहं मन्ये वायोरिव सुदुष्करम् ॥
cañcalaṁ hi manaḥ kṛṣṇa pramāthi balavad dṛḍham |
tasyāhaṁ nigrahaṁ manye vāyor iva suduṣkaram ||
(Śrīmad Bhagavad-gītā: 6.34)
“O Kṛṣṇa, because the mind is restless, agitating, powerful, and obstinate, I consider controlling it, like [trying to control] the wind, extremely difficult.”