Psalm 18 Jan. 8 For the Chief Musician. By David the servant of Yahweh, who spoke to Yahweh the words of this song in the day that Yahweh delivered him from the hand of all his enemies, and from the hand of Saul. He said,  1I love You, Yahweh, my strength. 2Yahweh is my rock, my fortress, and my deliverer; my God, my rock, in whom I take refuge; my shield, and the horn of my salvation, my high tower. 3I call on Yahweh, who is worthy to be praised; and I am saved from my enemies. 4The cords of death surrounded me, the floods of ungodliness made me afraid. 5The cords of Sheol were around me, the snares of death came on me. 6In my distress I called on Yahweh, and cried to my God. He heard my voice out of His temple; my cry before Him came into His ears. 7Then the earth shook and trembled, the foundations also of the mountains quaked and were shaken, because He was angry. 8Smoke went out of His nostrils, consuming fire came out of His mouth; coals were kindled by it. 9He bowed the heavens also, and came down, thick darkness was under His feet. 10He rode on a cherub, and flew. Yes, He soared on the wings of the wind. 11He made darkness His hiding place, His pavilion around Him, darkness of waters, thick clouds of the skies. 12At the brightness before Him His thick clouds passed, hailstones and coals of fire. 13Yahweh also thundered in the sky, the Most High uttered His voice: hailstones and coals of fire. 14He sent out His arrows, and scattered them; yes, great lightning bolts, and defeated them. 15Then the channels of waters appeared, the foundations of the world were laid bare at Your rebuke, Yahweh, at the blast of the breath of Your nostrils. 16He sent from on high. He took me, He drew me out of many waters. 17He delivered me from my strong enemy, from those who hated me; for they were too mighty for me. 18They came on me in the day of my calamity, but Yahweh was my support. 19He brought me forth also into a large place. He delivered me, because He delighted in me. 20Yahweh has judged me according to my righteousness, according to the cleanness of my hands has He recompensed me. 21For I have kept the ways of Yahweh, and have not wickedly departed from my God. 22For all His ordinances were before me, I didn’t put away His statutes from me. 23I was also blameless with Him, I kept myself from my iniquity. 24Therefore Yahweh has rewarded me according to my righteousness, according to the cleanness of my hands in His eyesight. 25With the merciful You will show Yourself merciful. With the perfect man, You will show Yourself perfect. 26With the pure, You will show Yourself pure; with the crooked You will show Yourself shrewd. 27For You will save the afflicted people, but the proud eyes You will bring down. 28For You will light my lamp, Yahweh. My God will light up my darkness. 29For by You I advance through a troop. By my God, I leap over a wall. 30As for God, His way is perfect. The word of Yahweh is tried in the furnace. He is a shield to all those who take refuge in Him. 31For who is God, except Yahweh? Who is a rock besides our God, 32the God who arms me with strength, and makes my way perfect? 33He makes my feet like deer’s feet, and sets me on my high places. 34He teaches my hands to war, so that my arms bend a bow of bronze. 35You have also given me the shield of Your salvation. Your right hand sustains me. Your gentleness has made me great. 36You have enlarged my steps under me, My feet have not slipped. 37I will pursue my enemies, and overtake them. Neither will I turn again until they are consumed. 38I will strike them through, so that they will not be able to rise. They shall fall under my feet. 39For You have armed me with strength to the battle, You have subdued under me those who rose up against me. 40You have also made my enemies turn their backs to me, that I might cut off those who hate me. 41They cried, but there was none to save; even to Yahweh, but He didn’t answer them. 42Then I beat them small as the dust before the wind. I cast them out as the mire of the streets. 43You have delivered me from the strivings of the people, You have made me the head of the nations. A people whom I have not known shall serve me. 44As soon as they hear of me they shall obey me; the foreigners shall submit themselves to me. 45The foreigners shall fade away, and shall come trembling out of their close places. 46Yahweh lives; and blessed be my rock. Exalted be the God of my salvation, 47even the God who executes vengeance for me, and subdues peoples under me. 48He rescues me from my enemies. Yes, You lift me up above those who rise up against me. You deliver me from the violent man. 49Therefore I will give thanks to You, Yahweh, among the nations, and will sing praises to Your name. 50He gives great deliverance to His king, and shows grace to His anointed, to David and to his seed, forevermore.   

Commentary

18:5 ‘Sheol’ is the Hebrew word translated “hell” in some Bibles; it is paralleled here with “death” (:4, “the cords of death” are “the cords of Sheol”) and is elsewhere translated “the grave”. It’s not a place where the wicked go for eternal torment; David was a righteous man, and he too went to the grave, or sheol.
18:16 He drew me out of many waters- This is an allusion to the name ‘Moses’ which means just this (Ex. 2:10); :19 alludes to how Israel were brought out of Egypt to the large place of Canaan, and there are many other Moses / Exodus allusions in this Psalm. We like David are to see similarities between our lives and those of Bible characters, taking them as our warnings, inspiration and friends, as David evidently understood Moses. And of course we will one day eternally be united with our heroes and encouragers in faith. 
18:22-24 David speaks like this of his own righteousness, although this Psalm was written in later life, after his sin with Bathsheba (:1 = 2 Sam. 22:1). He can only speak like this because he had learnt the lesson that God’s righteousness really is imputed to us who are sinners; and he rejoices in this reality, believing it to the point that he really felt it and his self-perception reflected it.
18:30 The word of Yahweh is tried in the furnace- The experiences of our lives are like the intense fire of a furnace, and God’s word like gold comes through those tests; it is proved not only true but wonderful and beautiful, time and again.
18:43 You have made me the head of the nations- But David speaks in :44 as if this had not yet happened. He imagined the things he prayed for as having already happened, just as Jesus taught we should too (Mt. 21:22 Gk.). God speaks of those things which don’t exist as if they do, so certain are they of coming to pass (Rom. 4:17), and we are asked to have this same perspective when it comes to prayer.
18:49 I will give thanks to You, Yahweh, among the nations- God’s intention was that Israel should be a missionary nation, the light of the Gentile world. But generally they failed to perceive this; David was one of the few who did, because his Psalms often speak of telling the Gentile nations how great God is. He came to this simply from the colossal desire he had to praise God as widely and far as possible because of what God had done for him personally by grace. We should be likewise motivated to take the Gospel o the world around us, on the basis of simply having to tell others the wonderful things which we personally have experienced from God.