Which is the third commandment? – Shorter Westminster Catechism

The third commandment is, Thou shalt not take the name of the Lord thy God in vain; for the Lord will not hold him guiltless that taketh his name in vain.

Shorter Westminster Catechism

What are the reasons annexed to the second commandment? – Shorter Westminster Catechism

What is required in the third commandment? – Shorter Westminster Catechism