Thou shalt not take the name of the Lord thy God in vain.

[Christian3]

What exactly does taking the name of the Lord thy God in vain mean?

Thanks.

[rogue06]

FWIU, it isn't saying things like God [darn] it as commonly believed, because you can legitimately ask God to damn or curse something. Instead it means to either curse God or more likely to swear by God (taking an oath or vow) that you don't intend on keeping or pretending to do something in His name and not doing so. IOW, making a false oath. See Leviticus 19:12

[Christian3]

FWIU, it isn't saying things like God [darn] it as commonly believed, because you can legitimately ask God to damn or curse something. Instead it means to either curse God or more likely to swear by God (taking an oath or vow) that you don't intend on keeping or pretending to do something in His name and not doing so. IOW, making a false oath. See Leviticus 19:12

This is what Rabbi Joseph Telushkin says about this subject in his book: “Jewish Literacy.”
“The Third Commandment also has not fared well in English. Lo tissa et shem Ha-Shem Eloheikha la-shaw is usually translated as “You shall not take the Lord Your God’s name in vain.” Many people think that this means that you have to write God as G-D, or that it is blasphemous to say words such as “goddam.” Even if these assumptions are correct, it’s still hard to figure out what makes this offsense so heinous that it’s included in the document that forbids murdering, stealing, idolatry, and adultery. However, the Hebrew Lo tissa, literally means “You shall not carry [God’s name in vain]”; in other words, don’t use God as your justification in selfish causes. The Third Commandment is the only one concerning which God says, “for the Lord God will not forgive him who carries His name in vain” (Exodus 20:6-7).

The reason now seems to be clear. When a person commits an evil act, he discredits himself. But when a religious person commits an evil act in the name of God, he or she discredits God as well. And since God relies on religious people to bring knowledge of Him into the world, He pronounces this sin unpardonable.

[Chuckz]

What does it mean to take the Lord’s name in vain?

https://www.gotquestions.org/Lords-name-vain.html