Setting aside of day of rest each week was a revolutionary concept when it was first introduced as the Fourth Commandment. But this Commandment does more: it extends that day of rest to slaves and animals and thus set in motion the slow process of ending slavery and the compassionate treatment of animals. As Dennis Prager explains, the power of the Fourth Commandment to change your life is no less real today than it was for our ancient ancestors. Just ask the spouse of a workaholic how she would feel if her husband took off a day each week to spend with family and friends.