PSALM 4:8 I will both lay me down in peace, and sleep:

Having reconciled us to God by the blood of His cross, Christ is "our Peace," as the apostle says. He is called so, first, because He restores us to a state of friendship with God; and, secondly, because a sense of that fills the whole soul with a peace which passeth understanding. So, speaking of the righteousness which Christ wrought out for us, the prophet says, "The work of righteousness is peace"--His righteousness being the root, and our peace the fruit--that the spring, and this the stream. To describe for the comfort of the Church the constancy of the last and the fulness of the first, another prophet borrows two of nature's grandest images, "Thy peace shall be like a river, and thy righteousness like the waves of the sea"--the believer's peace flowing like a broad, deep stream, with life in its waters and smiling verdure on its banks; and a Saviour's righteousness covering all his sins, as the waves do the countless sands of their shore, when, burying them out of sight, the tide converts the whole reach of dull, dreary sand into a broad liquid mirror, to reflect the light of the sky and the beams of the sun.