Another use of the moral law is, that it may be a rule of divine worship and of a Christian life. “Thy word is a lamp unto my feet, and a light unto my path.” “I will put my law in their inward parts, and write it in their hearts, and cause you to walk in my statutes.” (Ps. 119:105. Jer. 31:33. Ez. 36:26.) This use of the law is peculiar to the regenerate. For although the law be also a rule of life to the unregenerate before their conversion, yet it is not to them a rule of worship and gratitude to God, as in the case of the regenerate.
—Zacharias Ursinus, The Commentary of Dr. Zacharias Ursinus on the Heidelberg Catechism, trans. G. W. Williard (Cincinnati, OH: Elm Street Printing Company, 1888), 614.