CHAPTER 13 Apr. 27 
Warning against Idolatry
If there should arise in the midst of you a prophet or a dreamer of dreams, and he gives you a sign or a wonder, 2and the sign or the wonder comes to pass of which he spoke to you saying, Let us go after other gods (which you have not previously known) and let us serve them, 3you must not listen to the words of that prophet or to that dreamer of dreams, for Yahweh your God proves you, to know whether you love Yahweh your God with all your heart and with all your soul. 4You must walk after Yahweh your God and fear Him and keep His commandments and obey His voice, and you must serve Him and cleave to Him. 5That prophet or that dreamer of dreams must be put to death, because he has spoken rebellion against Yahweh your God, Who brought you out of the land of Egypt and redeemed you out of the house of bondage, to draw you aside out of the way which Yahweh your God commanded you to walk in. So you must put away the evil from the midst of you. 6If your brother, the son of your mother, or your son or your daughter, or the wife of your bosom or your friend, who is as your own soul, entices you secretly, saying, Let us go and serve other gods, which you have not known, you nor your fathers, 7of the gods of the peoples who are around you, near to you or far off from you, from the one end of the land to the other end of the land, 8you must not consent to him nor listen to him. Neither shall your eye pity him, neither shall you spare, neither shall you conceal him, 9but you must surely kill him. Your hand shall be first on him to put him to death, and afterwards the hand of all the people. 10You must stone him to death with stones because he has sought to draw you away from Yahweh your God who brought you out of the land of Egypt, out of the house of bondage. 11All Israel shall hear, and fear, and shall not do any more such wickedness as this is in the midst of you. 12If you hear concerning one of your cities which Yahweh your God gives you to dwell there saying, 13Certain bad men have gone out from the midst of you and have drawn away the inhabitants of their city, saying Let us go and serve other gods, which you have not known, 14then you shall inquire and make search and ask diligently. Behold, if it is true and certain that such abomination is done in the midst of you, 15you must surely strike the inhabitants of that city with the edge of the sword, destroying it utterly and all that is therein and its livestock, with the edge of the sword. 16You shall gather all its spoil into the midst of its street and shall burn with fire the city and all its spoil, everything, to Yahweh your God, and it shall be a heap forever. It shall not be built again. 17Nothing of the devoted thing must cling to your hand, that Yahweh may turn from the fierceness of His anger and show you mercy and have compassion on you and multiply you, as He has sworn to your fathers, 18when you listen to the voice of Yahweh your God, to keep all His commandments which I command you this day, to do that which is right in the eyes of Yahweh your God.

Commentary

13:3 The reasoning here is helpful with respect to the claims made by some to perform supernatural feats. Even if it seems they might have done so, that isn’t a good enough reason to believe them; our loyalty to the one true God must not be swayed by apparently impressive deeds or predictions by those who don’t believe in Him.
13:5 Moses' frequent references to the way in which the Exodus had separated Israel from Egypt show the colossal difference there is between us and this world as a result of our Red Sea baptism into Christ (13:5; 15:15; 16:12; 1 Cor. 10:1,2); as our Lord in his time of dying was so strongly aware of the way in which He was redeeming us from this present evil world (Gal. 1:4). 
13:6 So often family loyalties deflect a person from their loyalty to the one true God. The same has always been the case. Our spiritual family should ultimately be more meaningful to us than our natural family; that at least is the ideal, although all families have their dysfunctions, including our spiritual family.
13:14 You shall inquire and make search and ask diligently- Allegations of misbehaviour or wrong teaching within the family of God must be taken seriously and not pushed under the carpet. But they aren’t to be acted upon without a very careful investigation, during which the love which believes and hopes all things is paramount. This passage cannot be used as a reason to divide from those who have a slightly different Biblical interpretation of something than we do, whilst believing in and worshipping the same Lord. The situation envisaged is if someone were seeking to draw Yahweh’s people away to a totally different god (:13).