which commandment is the third of the ten commandments?
The third of the Ten Commandments is: Thou shalt not take the name of the Lord thy God in vain. The context identifies verse 7 as the third command, warning that the Lord will not hold him guiltless who taketh His name in vain. It follows the first two commandments and precedes the fourth command about remembering the Sabbath day.
Les explains that verse 7 is the third command: "Thou shalt not take the name, and here it comes again, of the Lord thy God." He notes that "the Lord thy God" is attached to every one of the first five commandments. The command continues, "For the Lord will not hold him guiltless, who taketh his name in vain." Then Les moves to the fourth command, "Remember the Sabbath day, to keep it holy," noting that verse 9 is part of that commandment just as well as verse 8.
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.