Abba Lot went to Abba Joseph and said: 'Abba, as far as I can, I keep a moderate rule, with a little fasting, and prayer, and meditation, and quiet: and as far as I can I try to cleanse my heart of evil thoughts. What else should I do?' Then the old man rose, and spread out his hands to heaven, and his fingers shone like ten candles, and he said: 'if you will, you could become a living flame'.

from Chadwick's Western Asceticism, cited here.