This psalm is an almost complete acrostic.

According to the Harper Bible Commentary, the focus on the individual (rather than on the nation) argues for a post-exilic date.  The indication from v25 is that the author was of later years.  The psalm reflects some of the characteristics of wisdom literature, yet ‘one finds that unlike Proverbs it does not seek to form disciples and unlike Job it does not seek to solve problems. Rather it provides points for meditation and for preaching within the postexilic assembly.’

Psa 37:1 Of David. Do not fret because of evil men or be envious of those who do wrong;

Psa 37:2 for like the grass they will soon wither, like green plants they will soon die away.

Psa 37:3 Trust in the LORD and do good; dwell in the land and enjoy safe pasture.

Psa 37:4 Delight yourself in the LORD and he will give you the desires of your heart.

Psa 37:5 Commit your way to the LORD; trust in him and he will do this:

Psa 37:6 He will make your righteousness shine like the dawn, the justice of your cause like the noonday sun.

Psa 37:7 Be still before the LORD and wait patiently for him; do not fret when men succeed in their ways, when they carry out their wicked schemes.

Psa 37:8 Refrain from anger and turn from wrath; do not fret—it leads only to evil.

Psa 37:9 For evil men will be cut off, but those who hope in the LORD will inherit the land.

Psa 37:10 A little while, and the wicked will be no more; though you look for them, they will not be found.

Psa 37:11 But the meek will inherit the land and enjoy great peace.

Great peace – ‘Perhaps they have not abundance of wealth to delight in; but they have that which is better, abundance of peace, inward peace and tranquility of mind, peace with God, and then peace in God, that great peace which those have that love God’s law, whom nothing shall offend (Ps. 119:165), that abundance of peace which is in the kingdom of Christ (Ps. 72:7), that peace which the world cannot give (Jn. 14:27), and which the wicked cannot have, Isa. 57:21.’ (MHC)

Psa 37:12 The wicked plot against the righteous and gnash their teeth at them;

Psa 37:13 but the Lord laughs at the wicked, for he knows their day is coming.

Psa 37:14 The wicked draw the sword and bend the bow to bring down the poor and needy, to slay those whose ways are upright.

Psa 37:15 But their swords will pierce their own hearts, and their bows will be broken.

Psa 37:16 Better the little that the righteous have than the wealth of many wicked;

Psa 37:17 for the power of the wicked will be broken, but the LORD upholds the righteous.

Psa 37:18 The days of the blameless are known to the LORD, and their inheritance will endure for ever.

Psa 37:19 In times of disaster they will not wither; in days of famine they will enjoy plenty.

Psa 37:20 But the wicked will perish: The LORD’s enemies will be like the beauty of the fields, they will vanish—vanish like smoke.

Psa 37:21 The wicked borrow and do not repay, but the righteous give generously;

Psa 37:22 those the LORD blesses will inherit the land, but those he curses will be cut off.

Psa 37:23 If the LORD delights in a man’s way, he makes his steps firm;

Psa 37:24 though he stumble, he will not fall, for the LORD upholds him with his hand.

Psa 37:25 I was young and now I am old, yet I have never seen the righteous forsaken or their children begging bread.

I was young and now I am old – ‘Let old people make it their business to tell what they have seen of God’s wonders in providence and in grace.  They cannot be better employed than in thus commending the loving-kindness of the Lord to the rising generation.’ (Plumer)

‘There is a sad kind of feeling which a man has when he is constrained to say, “I have been young;” for it suggests the memory of joys, and hopes, and friends, that are now gone for ever. But a man may have some claim to respect for his opinions when he is constrained to say it; for he can bring to the coming generation such results of his own experience and observation as may be of great value to those who are “young.”’ (Barnes)

Forsaken – not by God, or by the people of God.

‘Job’s comforters would grant no exceptions to [the literal sense of this truth]; but Paul, and others before him, knew of an abundance which might be material or spiritual, as God saw fit (e.g. Ps. 73:26; Hab. 3:17f.; Matt. 4:4; 2 Cor. 6:10; Phil. 4:12).’ (Kidner)

Verses 21 and 26 clarify that the generosity of the believing community contributes in large measure to this happy state.

Matthew Henry: ‘It is not now universally true that the “righteous” are not “forsaken,” in the sense that they do not want, or in the sense that their children are not constrained to beg their bread, but the following things, are true: (a) that religion tends to make men industrious, economical, and prudent, and hence tends to promote prosperity, and to secure temporal comforts; (b) that religion of itself impoverishes no one, or makes no one the poorer; (c) that religion saves from many of the expenses in life which are produced by vicious indulgence; and (d) that, as a general rule, it saves men and their children from the necessity of public begging, and from the almshouse.’

Psa 37:26 They are always generous and lend freely; their children will be blessed.

The generosity of the righteous to one another is one reason why v25 holds true in so many (but not all) instances.

Psa 37:27 Turn from evil and do good; then you will dwell in the land for ever.

Psa 37:28 For the LORD loves the just and will not forsake his faithful ones. They will be protected for ever, but the offspring of the wicked will be cut off;

Psa 37:29 the righteous will inherit the land and dwell in it for ever.

Psa 37:30 The mouth of the righteous man utters wisdom, and his tongue speaks what is just.

Psa 37:31 The law of his God is in his heart; his feet do not slip.

Psa 37:32 The wicked lie in wait for the righteous, seeking their very lives;

Psa 37:33 but the LORD will not leave them in their power or let them be condemned when brought to trial.

Psa 37:34 Wait for the LORD and keep his way. He will exalt you to inherit the land; when the wicked are cut off, you will see it.

Psa 37:35 I have seen a wicked and ruthless man flourishing like a green tree in its native soil,

Psa 37:36 but he soon passed away and was no more; though I looked for him, he could not be found.

Psa 37:37 Consider the blameless, observe the upright; there is a future for the man of peace.

Psa 37:38 But all sinners will be destroyed; the future of the wicked will be cut off.

Psa 37:39 The salvation of the righteous comes from the LORD; he is their stronghold in time of trouble.

Psa 37:40 The LORD helps them and delivers them; he delivers them from the wicked and saves them, because they take refuge in him.