Deuteronomy 29:18

Lest there should be among you man or woman, or family, or
tribe
These words stand in connection with ( Deuteronomy 29:15 ) , with ( Deuteronomy 29:16 Deuteronomy 29:17 ) being in a parenthesis, as may be observed, and show the design of this solemn appearance of the people, and their entering afresh into covenant; which was to prevent their falling into idolatry, and preserve them from it, whether a single person of either sex, or a whole family, or even a tribe, which might be in danger of being infected with it, and so all the people:

whose heart turneth away this day from the Lord our God, to go [and]
serve the gods of those nations;
whose heart is enticed and drawn aside at the remembrance of the idols he has seen worshipped by others; and is looking off from the Lord God, his faith in him being weakened, his fear of him removed, and his affections for him lessened; and is looking towards the idols of the nations, with a hankering mind to serve and worship them:

lest there should be among you a root that beareth gall and wormwood:
the word "rosh", which we render "gall", signifies, according to Jarchi, a bitter herb, which better suits with a root than gall, and is elsewhere by us rendered "hemlock", ( Hosea 10:4 ) ; and is by him very rightly interpreted of a wicked man among them; for not a principle of immorality, or heresy, rooted in the mind, productive of bitter fruits, or evil actions, is meant; but a bad man, particularly an idolater, who is rooted in idolatry, and is guilty of and commits abominable actions; the issue of which will be bitterness and death, if not recovered; which agrees with what the apostle says, ( Hebrews 12:15 ) ; who manifestly alludes to this passage; see the Apocrypha:

``In those days went there out of Israel wicked men, who persuaded many, saying, Let us go and make a covenant with the heathen that are round about us: for since we departed from them we have had much sorrow.'' (1 Maccabees 1:11)

and is confirmed by what follows.