The god of the Jews repeatedly told them to get rid of indigenous population and if they did not completely get rid of them, God said that he will punish them. See Numbers 33:55 of the Jews Bible.
Numbers 33:55 If you don’t force out all the people there, they will be like pointed sticks in your eyes and thorns in your back. They will always be trouble for you, 56 and I will treat you as cruelly as I planned on treating them.
Joshua 23:12-13 Don’t ever turn your backs on him by marrying people from the nations that are left in the land. Don’t even make friends with them. I tell you that if you are friendly with those nations, the Lord won’t chase them away when you attack. Instead, they will be like a trap for your feet, a whip on your back, and thorns in your eyes.