Deuteronomy 13, Violating the Third Commandment

Here we look at the third commandment.  What does it mean to take God's name "in vain"? Any type of spiritual deceit in the name of YHWH is tasking His name in vain.

Deuteronomy 13: 1-5, False prophets

If a prophet, or one who foretells by dreams, appears among you and announces to you a miraculous sign or wonder, and if the sign or wonder of which he has spoken takes place, and he says, "Let us follow other gods" (gods you have not known) "and let us worship them,"  you must not listen to the words of that prophet or dreamer. The LORD your God is testing you to find out whether you love him with all your heart and with all your soul.

It is the LORD your God you must follow, and him you must revere. Keep his commands and obey him; serve him and hold fast to him.

That prophet or dreamer must be put to death, because he preached rebellion against the LORD your God, who brought you out of Egypt and redeemed you from the land of slavery; he has tried to turn you from the way the LORD your God commanded you to follow. You must purge the evil from among you.

Those who "preach rebellion" against YHWH, using claims of dreams or prophets, are violating the third commandment.

Deuteronomy 13: 6-11, Even your own family

If your very own brother, or your son or daughter, or the wife you love, or your closest friend secretly entices you, saying, "Let us go and worship other gods" (gods that neither you nor your fathers have known, gods of the peoples around you, whether near or far, from one end of the land to the other), do not yield to him or listen to him. 

Show him no pity. Do not spare him or shield him. You must certainly put him to death. Your hand must be the first in putting him to death, and then the hands of all the people. Stone him to death, because he tried to turn you away from the LORD your God, who brought you out of Egypt, out of the land of slavery.

Then all Israel will hear and be afraid, and no one among you will do such an evil thing again.

Even evil within one's own family was to be treated harshly.

Deuteronomy 13: 12-15, A town in rebellion

If you hear it said about one of the towns the LORD your God is giving you to live in that wicked men have arisen among you and have led the people of their town astray, saying, "Let us go and worship other gods" (gods you have not known), then you must inquire, probe and investigate it thoroughly. And if it is true and it has been proved that this detestable thing has been done among you, you must certainly put to the sword all who live in that town. Destroy it completely, both its people and its livestock.

It is possible an entire town might be in rebellion. Currid's commentary says that the Hebrew phrase translated "wicked men" is literally "sons of Belial". The term "Belial" is used again in Deuteronomy 15:9 for wickedness.  Ancient Hebrew seemed to view Belial as a personification of wickedness or worthlessness.

Deuteronomy 13: 16-18, Devastation

Gather all the plunder of the town into the middle of the public square and completely burn the town and all its plunder as a whole burnt offering to the LORD your God. It is to remain a ruin forever, never to be rebuilt. None of those condemned things shall be found in your hands, so that the LORD will turn from his fierce anger; he will show you mercy, have compassion on you, and increase your numbers, as he promised on oath to your forefathers, because you obey the LORD your God, keeping all his commands that I am giving you today and doing what is right in his eyes.

In the new Promised Land, a town in rebellion against YHWH is to be destroyed.  The future land is to be fully committed to YHWH.

The word translated "ruin" here is tel or "tell" which has taken the meaning, in archaeology, of a mound of debris left over from a city.