Judges 2:3

Therefore I also said, I will not drive them out from before you, but they shall be [as thorns] in your sides, and their gods shall be a snare to you.

Numbers 33:55

But if ye will not drive out the inhabitants of the land from before you, then those that ye let remain of them shall be as pricks in your eyes, and as thorns in your sides, and they shall vex you in the land in which ye dwell.

Joshua 23:13

know for a certainty that LORD your God will no more drive these nations from out of your sight, but they shall be a snare and a trap to you, and a scourge in your sides, and thorns in your eyes, until ye perish from off this good

Deuteronomy 7:16

And thou shall consume all the peoples that LORD thy God shall deliver to thee. Thine eye shall not pity them. Neither shall thou serve their gods, for that will be a snare to thee.

Judges 2:21

I also will not henceforth drive out any from before them of the nations that Joshua left when he died,

Judges 3:6

And they took their daughters to be their wives, and gave their own daughters to their sons and served their gods.

Psalm 106:36

and served their idols, which became a snare to them.

Exodus 23:33

They shall not dwell in thy land, lest they make thee sin against me, for if thou serve their gods, it will surely be a snare to thee.

Exodus 34:12

Take heed to thyself, lest thou make a covenant with the inhabitants of the land where thou go, lest it be for a snare in the midst of thee.

1 Kings 11:1-7

Now king Solomon loved many foreign women, together with the daughter of Pharaoh, women of the Moabites, Ammonites, Edomites, Sidonians, and Hittites,

Treasury of Scripture Knowledge

Summary

Wherefore I also said, I will not drive them out from before you; but they shall be as thorns in your sides, and their gods shall be a snare unto you.

Bible References

I also said

Judges 2:21
I also will not henceforth drive out any from before them of the nations that Joshua left when he died,
Numbers 33:55
But if ye will not drive out the inhabitants of the land from before you, then those that ye let remain of them shall be as pricks in your eyes, and as thorns in your sides, and they shall vex you in the land in which ye dwell.
Joshua 23:13
know for a certainty that LORD your God will no more drive these nations from out of your sight, but they shall be a snare and a trap to you, and a scourge in your sides, and thorns in your eyes, until ye perish from off this good

Their gods

Judges 3:6
And they took their daughters to be their wives, and gave their own daughters to their sons and served their gods.
Exodus 23:33
They shall not dwell in thy land, lest they make thee sin against me, for if thou serve their gods, it will surely be a snare to thee.
Exodus 34:12
Take heed to thyself, lest thou make a covenant with the inhabitants of the land where thou go, lest it be for a snare in the midst of thee.
Deuteronomy 7:16
And thou shall consume all the peoples that LORD thy God shall deliver to thee. Thine eye shall not pity them. Neither shall thou serve their gods, for that will be a snare to thee.
1 Kings 11:1
Now king Solomon loved many foreign women, together with the daughter of Pharaoh, women of the Moabites, Ammonites, Edomites, Sidonians, and Hittites,
Psalm 106:36
and served their idols, which became a snare to them.

General references

Deuteronomy 6:19
to thrust out all thine enemies from before thee, as LORD has spoken.
Deuteronomy 20:18
that they not teach you to do after all their abominations, which they have done to their gods, so ye would sin against LORD your God.
Deuteronomy 28:43
The sojourner who is in the midst of thee shall mount up above thee higher and higher, and thou shall come down lower and lower.
Judges 2:21
I also will not henceforth drive out any from before them of the nations that Joshua left when he died,
1 Samuel 8:8
According to all the works which they have done since the day that I brought them up out of Egypt even to this day, in that they have forsaken me, and served other gods, so do they also to thee.