Adam Clarke on Joshua 23:7

Come not among these nations - Have no civil or social contracts with them, (see Jos 23:12), as these will infallibly lead to spiritual affinities, in consequence of which ye will make honorable mention of the name of their gods, swear by them as the judges of your motives and actions, serve them in their abominable rites, and bow yourselves unto them as your creators and preservers; thus giving the whole worship of God to idols: and all this will follow from simply coming among them. He who walks in the counsel of the ungodly will soon stand in the way of sinners, and shortly sit in the seat of the scornful. Nemo repente fuit turpissimus. "No man rises to the highest stages of iniquity but by degrees." Nero himself, under the instructions of Seneca, was a promising youth.