Virtue is uncomplicated - Psalm 124 verses 3&4 (Gradual Psalm No 6/4)

Rubens

Verses 3&4 of Psalm 124 provide words of encouragement to the pilgrim perhaps assaulted by evildoers along the way. 

3	V	Quia non relínquet Dóminus virgam peccatórum super sortem justórum: * ut non exténdant justi ad iniquitátem manus suas.
	NV	Quia non requiescet virga iniquitatis super sortem iustorum, ut non extendant iusti ad iniquitatem manus suas.
	JH	Quia non requiescet uirga impietatis  super sortem iustorum,  ut non mittant iusti in iniquitatem manus suas.
		ὅτι οὐκ ἀφήσει τὴν ῥάβδον τῶν ἁμαρτωλῶν ἐπὶ τὸν κλῆρον τῶν δικαίων ὅπως ἂν μὴ ἐκτείνωσιν οἱ δίκαιοι ἐν ἀνομίᾳ χεῖρας αὐτῶν

Quia (for) non (not) relínquet (he will leave) Dóminus (the Lord) virgam (the rod) peccatórum (of sinners) super (over) sortem (the fate) justórum Of the just): ut (that) non (not) exténdant (they stretch out) justi (the just) ad (to) iniquitátem (inquity) manus (the hand) suas (his).

quia, conj. for, because, that. truly, surely, indeed

relinquo, liqui, lictum, ere 3,  to leave behind at death;  to allow, suffer, permit

virga, ae, ., a rod, staff, scepter, a shepherd's crook.

peccator, oris, m. a sinner, transgressor; the wicked, the godless.

super, prep, with ace. And abl  on, upon, over

sors, sortis, /.  lot, fate, destiny

extendo, tendi, tentum, ere 3,  to stretch out or forth; to extend, prolong, protract, continue;

justus, a, um  a just man, the just.

iniquitas, atis, / iniquity, injustice, sin.

manus, us, /.,  hand

DR	For the Lord will not leave the rod of sinners upon the lot of the just: that the just may not stretch forth their hands to iniquity.
Brenton	For the Lord will not allow the rod of sinners to be upon the lot of the righteous; lest the righteous should stretch forth their hands to iniquity.
MD	The Lord will not let the sinner’s rod weigh down on the lot of the just, lest the just extend their hands to evildoing.
RSV	For the scepter of wickedness shall not rest upon the land allotted to the righteous, lest the righteous put forth their hands to do wrong.
Knox	Domain of the just! No longer shall godless men bear rule in it; else the just, too, might soil their hands with guilt.
Cover	For the rod of the ungodly cometh not into the lot of the righteous, lest the righteous put their hand unto wickedness.
Grail	For the scepter of the wicked shall not rest over the land of the just for fear that the hands of the just should turn to evil.

Cassiodorus explains the rod thus: 

By rod is denoted the power of good and evil. In the good sense we have the words spoken of the Lord Saviour Himself: The Lord will send forth the rod of thy power out of Sion, and thou shalt rule in the midst of thy enemies. Moses too received a rod, with which he performed many miracles. In the bad sense it is given also to those who ever afflict the faithful with perverted zeal. Persecutors are a rod for martyrs; so too are masters angry with their households, as was Pharaoh, Nebuchad­nezzar and the others who ruled with the harshest tyranny.”

 For some periods of time, in other words, the psalmist suggests that God may allow the wicked to prosper, and oppress the good.  But he will never allow evil to continue unchecked forever, lest the good succumb to temptation. Thus, evil men may run the Church for a period and heresy may flourish, but eventually truth will be restored; unjust societies may seem to flourish for a period, but their time will end.

4	V/NV/JH	Bénefac, Dómine, bonis, * et rectis corde.
		ἀγάθυνον κύριε τοῖς ἀγαθοῖς καὶ τοῖς εὐθέσι τῇ καρδίᾳ

Benefac (do good), Domine (O Lord), bonis (to the good) et (and) rectis upright) corde (of heart).

benefacio, feci, factum, ere 3, to do well; to do good to, to deal kindly with.

bonus, a, um, good; morally good, upright

rectus, a, um, part. adj.  just, right, righteous, upright. the just, just men, the good. steadfast, stable, steady.

cor, cordis, n., the heart, regarded as the seat of the faculties, feelings, emotions, passions; the mind, the soul.

DR	Do good, O Lord, to those that are good, and to the upright of heart.
Brenton	Do good, O Lord, to them that are good, and to them that are upright in heart.
MD	Show Thy goodness Lord, to the good, and to the upright of heart.
RSV	Do good, O LORD, to those who are good, and to those who are upright in their hearts!
Knox	Deal kindly, Lord, with the kindly, with the true-hearted.
Cover	Do well, O Lord, unto those that are good and true of heart.
Grail	Do good, Lord, to those who are good, to the upright of heart;

This verse is a reminder to us that our God is a just God.  It is often suggested these days that God will forgive all, even those unrepentant in sin.  Yet this is not what Scripture and Tradition teaches.  St Basil the Great commented: 

God is good, but he is also just, and it is the nature of the just to reward in proportion to merit, as it is writ­ten: "Do good, O Lord, to those that are good and to the upright of heart. But such as turn aside to their own crooked ways, the Lord shall lead out with the workers of iniquity." He is merciful, but he is also a judge, for "the Lord loves mercy and judgment," says the psalmist.

 St John Chrysostom takes the argument a step further, suggesting that virtue is straightforward, while vice is much more varied: 

Now, here he names as upright the sincere, the unaffected, those with nothing hidden or festering below the surface. Uprightness is like that, you see, and it most of all God looks for everywhere. Virtue is like that, something uncom­plicated and simple, as in consequence vice is complicated, varied, devious - as you can see in reality itself. At any rate, people intent on deceiving and hatching plots - consider how many schemes they put their hands to, the number of different wiles they have need of, how many falsified stories, how much shrewdness. Those who speak the truth, on the other hand, have need of no effort, no difficulty, no hypocrisy, no scheming, nothing of that sort, as truth shines through of its own accord. In other words, just as bodies that are deformed require artifice on the outside and cover­ings to conceal the disfigurement of nature, whereas natural beauty is conspicuous of its own making, so too is it possible to discover falsehood and truth, vice and virtue. 

Vulgate	Douay-Rheims
Canticum graduum.
1 Qui confídunt in Dómino, sicut mons Sion: * non commovébitur in ætérnum, qui hábitat in Jerúsalem.	They that trust in the Lord shall be as mount Sion: he shall not be moved for ever that dwells 2 in Jerusalem.
2  Montes in circúitu ejus: * et Dóminus in circúitu pópuli sui, ex hoc nunc et usque in sæculum.	Mountains are round about it: so the Lord is round about his people from henceforth now and for ever.
3  Quia non relínquet Dóminus virgam peccatórum super sortem justórum: * ut non exténdant justi ad iniquitátem manus suas.	3 For the Lord will not leave the rod of sinners upon the lot of the just: that the just may not stretch forth their hands to iniquity.
4  Bénefac, Dómine, bonis, * et rectis corde.	4 Do good, O Lord, to those that are good, and to the upright of heart.
5  Declinántes autem in obligatiónes addúcet Dóminus cum operántibus iniquitátem: * pax super Israël.	5 But such as turn aside into bonds, the Lord shall lead out with the workers of iniquity: peace upon Israel.

And you can find notes on the last verse of this psalm here.