Q. 99. What is required in the third commandment?
A. That we, not only by cursing1 or perjury,2 but also by rash swearing,3 must not profane or abuse the name of God; nor by silence or connivance be partakers of these horrible sins in others; and, briefly, that we use the holy name of God no otherwise than with fear and reverence;4 so that He may be rightly confessed and worshiped by us,5 and be glorified in all our words and works.6

Q. 100. Is then the profaning of God’s name by swearing and cursing so heinous a sin that His wrath is kindled against those who do not endeavor, as much as in them lies, to prevent and forbid such cursing and swearing?
A. It undoubtedly is, for there is no sin greater or more provoking to God than the profaning of His name;7 and therefore He has commanded this sin to be punished with death.8