Put thy trust in Jehovah, and do good. The inspired writer now goes on, in the second place, to say, that every thing in the end shall be well with the righteous, because they are under the protection of God. But as there is nothing better or more desirable than to enjoy the fostering and protecting care of God, he exhorts them to put their trust in him, and at the same time to follow after goodness and truth. It is not without good reason that he begins with the doctrine of faith, or trust in God; for there is nothing more difficult for men than to preserve their minds in a state of peace and tranquillity, undisturbed by any disquieting fears, whilst they are in this world, which is subject to so many changes. On the other hand, while they see the wicked becoming rich by unjust means, extending their influence, and acquiring power by unrestrained indulgence in sin, it is no less difficult for them steadily to persevere in a life of piety and virtue. Nor is it sufficient merely to disregard those things that are commonly sought after with the greatest eagerness. Some of the philosophers of antiquity were so noble-minded, that they despised riches unjustly acquired, and abstained from fraud and robbery; nay, they held up to ridicule the vain pomp and splendor of the wicked, which the common people look upon with such high admiration. But as they were destitute of faith, they defrauded God of his honor, and so it happened that they never knew what it was to be truly happy. Now, as David places faith first in order, to show that God is the author of all good, and that by his blessing alone prosperity is to be looked for; so it ought to be observed that he connects this with a holy life: for the man who places his whole confidence in God, and gives himself up to be governed by him, will live uprightly and innocently, and will devote himself to doing good. Dwell in the land This language is much more expressive than if he had promised that the righteous should dwell securely in the land. [1] It is just as if he had led them to the place, and put them in possession of it. Moreover, by these words he declares that they shall long enjoy it. They are, it is true, only strangers or sojourners in this world, yet the hand of the Lord is stretched forth to protect them, so that they live in security and peace. This David again confirms by the following clause, Thou shalt be fed in truth Assured of the protection of God, he exhorts them to place entire and unsuspecting confidence in him. It is surprising to find how interpreters have wrested, and as it were mangled this clause, by the different meanings they have put upon it. Some take the verb to feed in an active signification; and others understand the expression to feed on faith as denoting to cherish within the heart the promises of God. Others are of opinion that David exhorts us to feed our brethren with faith by ministering to them the pure word of God, which is the spiritual food of the soul. Others render the term for faith in the sense of sincerity, so that the expression to feed on faith would signify to behave in an upright and honest manner among men. But the scope and connection of the passage necessarily require, and it is quite in accordance with the nature of the Hebrew language, that the verb rh, re-eh, should be taken in a passive signification, Be fed This, too, is the opinion of the greater part of commentators, who, notwithstanding, afterwards differ in explaining its meaning. Some of them adopt the interpretation, that we are fed with faith, when the promises of God suffice us, and we are satisfied with them. Others give this explanation, Feed thyself with the fruit of faith, because God will indeed show that we have not believed his word in vain. Others explain it in this way, Let truth be thy food, and let nothing give thee greater pleasure than to converse sincerely and frankly with thy neighbors. There is still another interpretation which, although in some respects different, is similar to the preceding, namely, Live not upon spoil, but be content with lawful sustenance; that is to say, with that which is lawfully acquired. It is certainly a shameful and disgraceful thing that so many learned men should have erred in a matter so plain and obvious. [2] Had not every one been led by his own ambition to seek for something new, the true and natural meaning of the prophet would have occurred at once, which is this, Dwell in the land, that thou mayest enjoy it in sure and lasting repose. The Hebrew word 'mvnh, emunah, not only signifies truth or faith, but also secure continuance for a long period. And who does not see that since the possession of the land was given to the righteous, this latter clause was added by way of exposition?

Footnotes

1 - Some read, "Thou shalt dwell in the land." The Hebrew verb is in the imperative mood; but the imperative in Hebrew is sometimes used for the future of the indicative. -- Glass. tom. 1, can. 40, p. 285.

2 - Modern critics have varied as much in their interpretations of this clause of the verse as those who preceded Calvin, of whom he complains. For example, Ainsworth reads, "Thou shalt be fed by faith;" Archbishop Secker," Thou shalt be fed in plenty;" Parkhurst, "Thou shalt be fed in security;" Dathe, "Tunc terram inhabitabis et secure vivas," assigning the reason for this translation to be, that "pascere securitatem, sive si malis, in securitate, nihil aliud est quam secure vivere;" and Gesenius reads, "Follow after truth," or, "seek to be faithful," deriving the verb from a root which signifies to take delight in, or to follow after.

Trust in the Lord - Confide in him; rest on him. Instead of allowing the mind to be disturbed and sad, because there are wicked men upon the earth; because they are prosperous and apparently happy; because they may injure you in your person or reputation Psalm 37:6, calmly confide in God. Leave all this in his hands. Feel that he rules, and that what he permits is wisely permitted; and that whatever may occur, it will all be overruled for his own glory and the good of the universe.
And do good - Be engaged always in some work of benevolence.
(a) If there are wicked men in the world, if wickedness abounds around us, there is the more reason for our endeavoring to do good. If others are doing evil, we should do good; if they are wicked, we cannot do a better work than to do good to them, for the best way of meeting the wickedness of the world is to do it good.
(b) The best way to keep the mind from complaining, chafing, and fretting, is to be always engaged in doing good; to have the mind always occupied in something valuable and useful. Each one should have so much of his own to do that he will have no thee to murmur and complain, to allow the mind to prey on itself, or to "corrode" for lack of employment.
So shalt thou dwell in the land - This would be more correctly translated as a command: "Dwell in the land." That is, abide safely or securely in the land - referring, perhaps, to "the land" as the land of promise - the country given to the people of God. The idea is, that they should abide there calmly and securely; that they should not worry themselves because there were wicked men upon the earth, and because they were successful, but that they should be thankful for their inheritance, and partake gratefully of the bounties which they receive from the hand of God. Compare the notes at Matthew 5:5.
And verily thou shalt be fed - Margin, "in truth or stableness." The "literal" meaning would be, "Feed on truth." The word rendered "fed" is here in the imperative mood. It properly means to feed, as a flock; and then, to feed upon anything in the sense of delighting in, or taking pleasure in anything, as if we found our support or sustenance in it; and here it means, doubtless, "Feed on truth;" that is, seek after truth; find delight in it; let it be the food of your souls. The word here rendered "verily" means, as in the margin, "truth:" and the meaning is, that they should seek after truth, and find their support and comfort in that. There are, then, in this verse, four things prescribed as duty, in order to keep the mind calm in view of the fact that wickedness abounds in the world:
(1) to confide in God;
(2) to be actively employed in doing good;
(3) to abide calmly and gratefully in the land which God has given us;
(4) to seek after truth, or a true view of the character and government of God as the great Ruler.
If people would do these things, there would be little complaining and fretting in the world.

Dwell in the land - Do not flee to foreign climes to escape from that providence which, for thy own good, denies thee affluence in thy own country.
And verily thou shalt be fed - God will provide for thee the necessaries of life: its conveniences might damp thy intellect in its inventions, and lead thee into idleness; and its superfluities would induce thee to pamper thy passions till the concerns of thy soul would be absorbed in those of the flesh and, after having lived an animal life, thou mightest die without God, and perish everlastingly.
The original, ורעה אמונה ureeh emunah, might be translated, "and feed by faith." The Septuagint has και ποιμανθησῃ επι τῳ πλουτῳ αυτης, and thou shalt feed upon its riches. The Vulgate Ethiopic, and Arabic, are the same. The Syriac, seek faith. The Chaldee, be strong in the faith. The Anglo-Saxon, and feeded thou shalt be in its welfare. Old Psalter, and thu sal be fed in ryches of it. But it is probable that אמונה emunah here signifies security. And thou shalt be fed in security.
Dr. Delaney supposed that the Psalm might have been written by David in the behalf of Mephibosheth, who, being falsely aecused by his servant Ziba, had formed the resolution to leave a land where he had met with such bad treatment. David, being convinced of his innocence, entreats him to dwell in the land, with the assurance of plenty and protection. It is more likely that it is addressed to the captives in Babylon; and contains the promise that they shall return to their own land, and again enjoy peace and plenty.

(c) Trust in the LORD, and do good; [so] shalt thou dwell in the land, and verily thou shalt be fed.
(c) To trust in God and do according to his will are sure signs that his providence will never fail us.

Trust in the Lord,.... Not in men, who are fading and perishing like the green grass and tender herb; nor in riches, which are very uncertain things; but in the Lord, in whom is everlasting strength; and with whom are riches and honour, yea, durable riches and righteousness; trust in him both for things temporal and spiritual, for soul and body, for time and eternity; the way to have peace and quietness of mind under all dispensations is to exercise faith on a promising God. The Targum is, "trust in the Word of the Lord", in the essential Word of God, the promised Messiah;
and do good; in general, all good actions, in faith, and as the fruits and effects of it, without trusting to them, but in the Lord; doing them in his strength, and with a view to his glory; or in particular, acts of beneficence to the poor, to which the encouragement follows;
so shalt thou dwell in the land; either in the land of Canaan, a continuance in which depended upon the obedience of the people of the Jews to the commands of God; see Isaiah 1:19; or rather in the good land which is afar off, the heavenly and better country, which those that trust in the Lord, and have that faith in Christ which works by love, shall dwell in to all eternity;
and verily thou shalt be fed; either temporally, shall have food and raiment, even all the necessaries of life; or spiritually, with the word and ordinances, and with Christ the bread of life now; and hereafter shall be fed by him, the Lamb in the midst of the throne, and by him led to fountains of living water: some read the words as an exhortation, and render them, "feed truth" (k), that is, teach it, as Abraham taught his household, and as faithful pastors feed with knowledge and understanding; or "feed by faith" (l), as the just live by it; or, as the Targum renders it, "be strong in faith", as Abraham was, Romans 4:20; or rather, "feed upon truth" (m), the word of truth, the Gospel of salvation, and the several truths and doctrines of it, which are food for faith, and nourish up to everlasting life.
(k) "pasce veritatem", Pagninus, Montanus. (l) "Pascere fide", Junius & Tremellius, Cocceius. (m) "Pasce te veritate", Gejerus; "ut alimentum tuum", Gussetius, Ebr. Comment. p. 942. "feed on faith", Ainsworth.

Trust--sure of safety.
shalt thou dwell--or, "dwell thou"; repose quietly.
verily . . . fed--or, "feed on truth," God's promise (Psalm 36:5; compare Hosea 12:1).

The "land" is throughout this Psalm the promised possession (Heilsgut), viz., the land of Jahve's presence, which has not merely a glorious past, but also a future rich in promises; and will finally, ore perfectly than under Joshua, become the inheritance of the true Israel. It is therefore to be explained: enjoy the quiet sure habitation which God gives thee, and diligently cultivate the virtue of faithfulness. The two imperatives in Psalm 37:3, since there are two of them (cf. Psalm 37:27) and the first is without any conjunctive Waw, have the appearance of being continued admonitions, not promises; and consequently אמוּנה is not an adverbial accusative as in Psalm 119:75 (Ewald), but the object to רעה, to pasture, to pursue, to practise (Syriac רדף, Hosea 12:2); cf. רעה, רע, one who interests himself in any one, or anything; Beduin râ‛â = ṣâḥb, of every kind of closer relationship (Deutsch. Morgenlnd. Zeitschr. v. 9). In Psalm 37:4, ויתן is an apodosis: delight in Jahve (cf. Job 22:26; Psalm 27:10; Isaiah 58:14), so will He grant thee the desire (משׁאלת, as in Psalm 20:5) of thy heart; for he who, entirely severed from the creature, finds his highest delight in God, cannot desire anything that is at enmity with God, but he also can desire nothing that God, with whose will his own is thoroughly blended in love, would refuse him.