Therefore, prepare your minds for action,{Literally, "gird up the loins of your mind"} be sober and set your hope fully on the grace that will be brought to you at the revelation of Jesus Christ--

 (iii) The Christian is chosen for obedience and for sprinkling by the blood of Jesus Christ. In the Old Testament there are three occasions when sprinkling with blood is mentioned. It may well be that all three were present in Peter's mind and that all three have something to contribute to the thought behind these words. 