The Deeper Symbolism of Freemasonry from The Meaning of Masonry by Walter Leslie Wilmshurst.

“whilst ‘the Master of the Lodge’ is a symbolical phrase denoting the will-power of man, which should enable him to be master of his own life, to control his own actions and keep down the impulses of his lower nature, even as the stroke of the Master’s gavel controls the Lodge and calls to order and obedience the Brethren under his direction.” [via]