Deuteronomy 13:2

2 and the sign or the wonder come to pass which he spoke to thee, saying, Let us go and serve other gods, which ye know not;

Deuteronomy 13:2 Meaning and Commentary

Deuteronomy 13:2

And the sign and wonder come to pass whereof he spake unto
thee
The sign he promised to give, or the miracle he proposed to do, to show the reality of his mission, and the truth of his doctrine, which is performed, or seemingly performed, by legerdemain, by magic art, or by the help of the devil; which the Lord sometimes suffered for the trial of the faith and obedience of his people, and for the hardening of others in their unbelief, and which issues in their destruction; see ( 2 Thessalonians 2:9-12 ) ,

saying, let us go after other gods (which thou hast not known), and let
us serve them;
other gods besides the one living and true God, the Creator of all things; strange gods, the idols of the people, as the Targum of Jonathan; such as they had never heard of, nor had any knowledge of, nor any benefit from, as they had of the Lord their God. Now the doctrines of these, and of their worship, are what the false prophet or dreamer is supposed to come with, and inculcate into the minds of the people; and for the confirmation of which, and in order to draw them into the reception of them, and act according to them, he proposed to give a sign or wonder.

Deuteronomy 13:2 In-Context

1 And if there arise within thee a prophet, or one who dreams a dream, and he gives thee a sign or a wonder,
2 and the sign or the wonder come to pass which he spoke to thee, saying, Let us go and serve other gods, which ye know not;
3 ye shall not hearken to the words of that prophet, or the dreamer of that dream, because the Lord thy God tries you, to know whether ye love your God with all your heart and with all your soul.
4 Ye shall follow the Lord your God, and fear him, and ye shall hear his voice, and attach yourselves to him.
5 And that prophet or that dreamer of a dream, shall die; for he has spoken to make thee err from the Lord thy God who brought thee out of the land of Egypt, who redeemed thee from bondage, to thrust thee out of the way which the Lord thy God commanded thee to walk in: so shalt thou abolish the evil from among you.

The Brenton translation of the Septuagint is in the public domain.