The word here and in Deuteronomy 32:32 rendered "gall," is in Hosea 10:4 translated "hemlock." It is the name of a plant of intense bitterness, and of quick growth; and is therefore repeatedly used in conjunction with "wormwood" (compare Jeremiah 9:15; Lamentations 3:19; Amos 6:12), to express figuratively the nature and effects of sin (compare the marginal references.). The herb is probably the poppy. Hence, the "water" (i. e. juice) "of gall" Jeremiah 8:14; Jeremiah 23:15 would be opium. This would explain its employment in the stupefying drink given to criminals at the time of execution (compare Psalm 69:21; Matthew 27:34), and the use of the word as synonymous with poison (compare Deuteronomy 32:33; Job 20:16).

Wormwood - is the plant "absinthium." It is used to denote metaphorically the distress and trouble which result from sin.

"The root that beareth gall and wormwood," means in this place any person lurking among them who is tainted with apostasy.

A root that beareth gall and wormwood - That is, as the apostle expresses it, Hebrews 3:12, An evil heart of unbelief departing from the living God; for to this place he evidently refers. It may also signify false doctrines, or idolatrous persons among themselves.

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 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.

"That there may not be among you," etc.: this sentence may be easily explained by introducing a thought which may be easily supplied, such as "consider this," or "do not forget what ye have seen, that no one, either man or woman, family or tribe, may turn away from Jehovah our God." - "That there may not be a root among you which bears poison and wormwood as fruit." A striking image of the destructive fruit borne by idolatry (cf. Hebrews 12:15). Rosh stands for a plant of a very bitter taste, as we may see from the frequency with which it is combined with לענה, wormwood: it is not, strictly speaking, a poisonous plant, although the word is used in Job 20:16 to denote the poison of serpents, because, in the estimation of a Hebrew, bitterness and poison were kindred terms. There is no other passage in which it can be shown to have the meaning "poison." The sense of the figure is given in plain terms in Deuteronomy 29:19, "that no one when he hears the words of this oath may bless himself in his heart, saying, I will prosper with me, for I walk in the firmness of my heart." To bless himself in his heart is to congratulate himself. שׁרירוּת, firmness, a vox media; in Syriac, firmness, in a good sense, equivalent to truth; in Hebrew, generally in a bad sense, denoting hardness of heart; and this is the sense in which Moses uses it here. - "To sweep away that which is saturated with the thirsty:" a proverbial expression, of which very different interpretations have been given (see Rosenmller ad h. l.), taken no doubt from the land and transferred to persons or souls; so that we might supply Nephesh in this sense, "to destroy all, both those who have drunk its poison, and those also who are still thirsting for it" (Knobel). But even if we were to supply ארץ (the land), we should not have to think of the land itself, but simply of its inhabitants, so that the thought would still remain the same.

Lest there should be among you man, or woman, or family, or tribe, whose heart turneth away this day from the LORD our God, to go and serve the gods of these nations; lest there should be among you {i} a root that beareth gall and wormwood;

(i) Such sin, as the bitter fruit of it might choke and destroy you.

29:18 A root - An evil heart inclining you to such cursed idolatry, and bringing forth bitter fruits.

gall: or, a poisonous herb

29:10-21 The national covenant made with Israel, not only typified the covenant of grace made with true believers, but also represented the outward dispensation of the gospel. Those who have been enabled to consent to the Lord's new covenant of mercy and grace in Jesus Christ, and to give up themselves to be his people, should embrace every opportunity of renewing their open profession of relation to him, and their obligation to him, as the God of salvation, walking according thereto. The sinner is described as one whose heart turns away from his God; there the mischief begins, in the evil heart of unbelief, which inclines men to depart from the living God to dead idols. Even to this sin men are now tempted, when drawn aside by their own lusts and fancies. Such men are roots that bear gall and wormwood. They are weeds which, if let alone, overspread the whole field. Satan may for a time disguise this bitter morsel, so that thou shalt not have the natural taste of it, but at the last day, if not before, the true taste shall be discerned. Notice the sinner's security in sin. Though he hears the words of the curse, yet even then he thinks himself safe from the wrath of God. There is scarcely a threatening in all the book of God more dreadful than this. Oh that presumptuous sinners would read it, and tremble! for it is a real declaration of the wrath of God, against ungodliness and unrighteousness of man.