Sings Bhagavad Gita:
यथा दीपो निवातस्थो नेङ्गते सोपमा स्मृता ।
योगिनो यतचित्तस्य युञ्जतो योगमात्मनः ॥६- १९॥
yathā dīpo nivātastho
ne’ngate so’pamā smṛtā,
yuñjato yogam ātmanaḥ (19)
When a lamp is kept where there is not a whiff of air, its wick burns steadily and the flame goes straight up-it does not tremble. So it is used as a simile for the subdued mind of a yogi who has completely given himself up to God.