Jñāneśvarī (commentary on the Bhagavadgītā) 6.414

6.414

cañcalaṃ hi manaḥ kṛṣṇa pramāthi balavad dṛḍham
tasyāhaṃ nigrahaṃ manye vāyor iva suduṣkaram
jeṃ buddhīteṃ saḷī |
niścayāteṃ ṭāḷī |
dhairyeṃsī hātaphaḷī |
miḷaūni jāya ||

It harasses the intellect, frustrates resolve, and slips away, mocking one's courage;