Charles H. Spurgeon on Psalms 91:13

Thou shalt tread upon the lion and adder. Over force and fraud shalt thou march victoriously; bold opponents and treacherous adversaries shall alike be trodden down. When our shoes are iron and brass lions and adders are easily enough crushed beneath our heel. The young lion and the dragon shalt thou trample under feet. The strongest foe in power, and the most mysterious in cunning, shall be conquered by the man of God. Not only from stones in the way, but from serpents also, shall we be safe. To men who dwell in God the most evil forces become harmless, they wear a charmed life, and defy the deadliest ills. Their feet come into contact with the worst of foes, even Satan himself nibbles at their heel, but in Christ Jesus they have the assured hope of bruising Satan under their feet shortly. The people of God are the real "George and the dragon, "the true lion kings and serpent tamers. Their dominion over the powers of darkness makes them cry, "Lord, even the devils are subject unto us through thy word."