Deuteronomy 29:18

Lest there be among you man or woman These words are to be considered as connected with Deuteronomy 29:14, and as signifying the end for which he engaged them to renew their covenant with God, that none of them might revolt from him to serve other gods. Lest there should be a root An evil heart inclining you to such cursed idolatry, and bringing forth bitter fruits: or rather, some secret or subtle apostate from the true God and his religion, secretly lurking and working as a root under ground, and spreading his poison to the infection of others; for both the foregoing and following words speak of some particular person. Gall and wormwood Which though for the present it may please his fancy, yet in the end will produce bitter fruits; not only distasteful to God, but also destructive to yourselves. The word which we translate gall, is thought to signify some noxious and poisonous herb, but what herb, is difficult to say. It is rendered hemlock, (Hosea 10:4,) and is commonly joined with wormwood, as here, Jeremiah 9:15; Lamentations 3:19; Amos 6:12. To this passage the apostle alludes Hebrews 12:15, Lest any root of bitterness springing up trouble you.