Ezekiel 20:20

Hallow my sabbaths; remember to keep them holy, employ them on holy works of God's solemn and public worship, and cease from servile and worldly businesses. A sign: see Ezekiel 20:12. As the Friday observed a rest is the sign of a Turk, the seventh day observed is the sign of a Jew, and distinguisheth: so it was of old, so it is now: the Christian sabbath is a sign between Christ and us. May know more fully, acknowledge it more openly, and in waiting on mine ordinances may know by experience what the almighty grace of your God can do.