The term 'Day of REST' is often used to refer to the Sabbath, which is a day of REST and worship observed by many religions. In Judaism, the Sabbath is known as Shabbat, which is derived from the Hebrew word for 'REST'. In Christianity, the Sabbath is referred to as the Sabbath, which is derived from the Hebrew word for 'CEASE'. Both terms refer to the same day of REST and worship, which is typically observed on the seventh day of the week.