When meditation is mastered, the mind is unwavering like the flame of a lamp in a windless place.
In the still mind, in the depths of meditation, the Self reveals itself. Beholding the Self by means of the Self, an aspirant knows the joy and peace of complete fulfillment.
Having attained that abiding joy beyond the senses, revealed in the stilled mind, he never swerves from the eternal truth. He desires nothing else, and cannot be shaken by the heaviest burden of sorrow.
From Bhagavad Gita VI, 19-22