Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
Deuteronomy Chapter 29
This and the following chapter contain the address of Moses to the people on the solemn renewal of the covenant. Consult the marginal references for proof of historical statements or explanation of obscure words.
Ability to understand the things of God is the gift of God (compare Co1 2:13-14); yet man is not guiltless if he lacks that ability. The people had it not because they had not felt their want of it, nor asked for it. Compare Co2 3:14-15.
That ye may prosper - literally, "that ye may act wisely." The connection of the two ideas of wisdom in conduct and prosperity in circumstances is noteworthy.
The covenant was national, and therefore embraced all the elements which make up the nation. The "little ones" would of course be represented by their parents or guardians; the absent Deu 29:15 by those present; nor were the servants and proselytes to be excluded (compare Act 2:39). The text is fairly alleged in justification of the Church's practice of admitting little ones into covenant with God by Baptism, and accepting promises made on their behalf by sponsors.
With him that is not here with us - i. e. as the Jews explain, posterity; which throughout all generations was to be taken as bound by the act and deed of those present and living.
Idols - See the margin, "dungy gods;" i. e. clods or stocks which can be rolled about (compare Lev 26:30).
The word here and in Deu 32:32 rendered "gall," is in Hos 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 Jer 9:15; Lam 3:19; Amo 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" Jer 8:14; Jer 23:15 would be opium. This would explain its employment in the stupefying drink given to criminals at the time of execution (compare Psa 69:21; Mat 27:34), and the use of the word as synonymous with poison (compare Deu 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.
Compare on the thought Jer 23:17. The secret and presumptuous sinner is meant who flatters himself that all is well and will be well with him, since he follows his own devices and prospers. Compare Psa 73:11 ff.
To add drunkenness to thirst - The sense is probably: "Himself, drinking iniquity like water, Job 15:16, he corrupts and destroys others who are thirsting for it or prone to it."
The sense of the whole passage from Deu 29:16 onward to Deu 29:20 may be exhibited thus: "Ye have seen the abominations of idolatry among the pagan. Do you therefore look diligently that there be no secret idolater among you; a root of bitterness to all about him. Let there be no one, I say, who when he hears the curses of the Law against this sin, flatters himself, saying within himself, 'All will be well, for I walk unmolested in my own self-chosen path; ' and thus acting, not only takes his own fill of sin, but destroys likewise every tempted brother within his reach, for the Lord will not spare him," etc.
The description is borrowed from the local features of the Dead Sea and its vicinity. The towns of the vale of Siddim were fertile and well watered (compare Gen 13:10) until devastated by the wrath of God Gen 19:24-25. The ruin of Israel and its land should be of the like sort (compare Lev 26:31-32; Psa 107:34; Zep 2:9). The desolate state of Palestine at present, and the traces of former fertility and prosperity, are attested by every traveler.
The secret things belong unto the Lord our God - This verse seems to be added as a solemn admonition on the part of Moses, in order to close the series of blessings and curses which he has delivered. The sense seems to be this: "The future, when and how these good and evil things will take effect, it lies with the Lord our God to determine; it pertains not to man's sphere and duty. God's revealed will is that which we must carry out." The 17th of our Articles of Religion concludes with much the same sentiment.