As a lamp standing in a windless place does not flicker, this is remembered as the simile, For the yogi of controlled mind, practicing the discipline (yoga) of the self (ātman).
“He does not waver, like a lamp sheltered from the wind” is the simile recalled for a man of discipline, restrained in thought and practicing self-discipline.
(19) As a lamp might stand in a windless place, unflickering—this likeness has been heard of such athletes of the spirit (yogin) who control their thought and practice integration of the self.
6.19 As a lamp kept in a windless place does not flicker, such is the simile thought of for the yogi whose mind is under control, and who is engaged in concentration on the Self.
6.19 'A lamp does not flicker in a windless place' --- that is the simile employed for the subdued mind of a Yogin who practices Yoga.
6.19 As a lamp placed in a windless spot does not flicker -- to such is compared the Yogi of controlled mind, practicing Yoga in the Self (or absorbed in the Yoga of the Self).