Theophylact of Ohrid
Catena Aurea · Johannesevangelium 10
Then said Jesus unto them again, Verily, verily, I say unto you, I am the door of the sheep. All that ever came before me are thieves and robbers: but the sheep did not hear them. I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture. The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly. All that ever came before Me are thieves and robbers.
Mystically, the thief is the devil, steals by wicked thoughts, kills by the assent of the mind to them, and destroys by acts.