"Psalm 5 is a psalm of prayer against the false teachers and the rebellious spirits. It harshly condemns both their glistening teaching and their works, by which-under the name of God-they do great harm to the pure Word of God and the true worship of God. The psalm prays for the righteous, that is, for the pure Word of God and the pure worship of God. In the last verse it promises that such a prayer will be heard and the rebellious spirits will be condemned. This psalm belongs to the Second and Third Commandments, in which we are commanded to keep both God's name and God's Word holy. It belongs to the First and Second Petitions of the Lord's Prayer, in which we pray that God's name, honor, and kingdom will be advanced."
Also, in the Large Catechism, Luther comments on Psalm 5:11 specifically when discussing the first article in the Apostle's Creed (I believe in God the Father Almighty, make of heaven and earth). He writes:
"Further, we also confess that God the Father has not only given us all that we have and see before our eyes, but He daily preserves and defends us against all evil and misfortune (Psalm 5:11). He directs all sorts of danger and disaster away from us. We confess that He does all this out of pure love and goodness, without our merit, as a kind Father. He cares for us so that no evil falls upon us...Now, all that we have, and whatever else is in heaven and upon the earth, is daily given, preserved, and kept for us by God. Therefore, it is clearly suggested and concluded that it is our duty to love, praise, and thank Him for these things without ceasing. In short, we should serve Him with all these things, as He demands and has taught in the Ten Commandments....For if we believed this teaching with the heart, we would also act according to it. We would not strut about proudly, act defiantly, and boast as though we had life, riches, power, honor, and such, of ourselves. We would not act as though others must fear and serve us, as is the practice of the wretched, perverse world. The world is drowned in blindness and abuses all the good things and God's gifts only for it own pride, greed, lust and luxury. It never once thinks about God, so as to thank Him or acknowledge Him as Lord and Creator.
This article ought to humble and terrify us all, if we believe it...We ought, therefore, daily to recite this article. We ought to impress it upon our mind and remember it by all that meets our eyes and by all good that falls to us. Wherever we escape from disaster or danger, we ought to remember that it is God who gives and does all these things. In these escapes we sense and see His fatherly heart and His surpassing love toward us. In this way the heart would be warmed and kindled to be thankful, and to use all such good things to honor and praise God."
The "good things" or "these things" Luther refers to are several of course, but prior to his comments above, he does list the following: body, soul, life, senses, reason, understanding, food drink, clothing, support, family, home, sun, moon, stars, day, night, air, fire, water, earth and its produce, birds, fish, beasts, grain, government, peace, security, and no matter how small an unimportant a thing it might be.
1 Give ear to my words, O Lord; consider my groaning.
2 Give attention to the sound of my cry, my King and my God, for to you do I pray.
3 O Lord, in the morning you hear my voice; in the morning I prepare a sacrifice for you and watch.
4 For you are not a God who delights in wickedness; evil may not dwell with you.
5 The boastful shall not stand before your eyes; you hate all evildoers.
6 You destroy those who speak lies; the Lord abhors the bloodthirsty and deceitful man.
7 But I, through the abundance of your steadfast love, will enter your house.
I will bow down toward your holy temple in the fear of you.
8 Lead me, O Lord, in your righteousness because of my enemies; make your way straight before me.
9 For there is no truth in their mouth; their inmost self is destruction;
their throat is an open grave; they flatter with their tongue.
10 Make them bear their guilt, O God; let them fall by their own counsels;
because of the abundance of their transgressions cast them out, for they have rebelled against you.
11 But let all who take refuge in you rejoice; let them ever sing for joy,
and spread your protection over them, that those who love your name may exult in you.
12 For you bless the righteous, O Lord; you cover him with favor as with a shield.
Lord Jesus Christ, You are the Light of the world and alone the Way to eternal life. Restrain the corrupters of Your Word and all the enemies of Your truth. Preserve the truth of Your Gospel in these latter days and in faithful teachers who will lead us in the way everlasting. Grant us to serve You in steadfast faith and a good conscience to our end. Amen.