A light, in a place where there is no air, flickers not; this has been cited as a simile to a yogi whose mind has been restrained, and who devotes himself to abstraction.
यथा दीपो निवातस्थो नेङ्गते सोपमा स्मृता। योगिनो यतचित्तस्य युञ्जतो योगमात्मनः॥