Take the case of the flaming sword; just as in it the natures of the fire and the steel are preserved distinct, so also are their two energies and their effects. For the energy of the steel is its cutting power, and that of the fire is its burning power, and the cut is the effect of the energy of the steel, and the burn is the effect of the energy of the fire: and these are kept quite distinct in the burnt cut, and in the cut burn, although neither does the burning take place apart from the cut after the union of the two, nor the cut apart from the burning: and we do not maintain on account of the twofold natural energy that there are two flaming swords, nor do we confuse the essential difference of the energies on account of the unity of the flaming sword. In like manner also, in the case of Christ, His divinity possesses an energy that is divine and omnipotent while His humanity has an energy such as is our own. And the effect of His human energy was His taking the child by the hand and drawing her to Himself, while that of His divine energy was the restoring of her to life.
St. John Damascene, Exposition of the Orthodox Faith, Book III, Chapter XV.