John Wesley on Hebrews 4:13

In his sight - It is God whose word is thus "powerful:" it is God in whose sight every creature is manifest; and of this his word, working on the conscience, gives the fullest conviction. But all things are naked and opened - Plainly alluding to the sacrifices under the law which were first flayed, and then (as the Greek word literally means) cleft asunder through the neck and backbone; so that everything both without and within was exposed to open view.