In Psalm 69, David has reached the depths of despair. He feels he is on the brink of destruction and can only cry out to God for help. In this psalm, it is especially clear that David was a type of Christ; many aspects of his life foreshadow that of Christ. Some verses are clearly Messianic and have been quoted in the New Testament as relating to the sufferings of Jesus, but other portions of the psalm relate only to the psalmist.
Terrible persecution had taken its toll on David. He had many hateful and powerful enemies who sought to destroy him, and yet it is without cause, for he has done no wrong; yet he must pay the penalty. Jesus confirmed the prophetic interpretation of this passage by saying that this was spoken of Him (69:4; John 15:25). Truly Jesus had not sinned, yet he payed the punishment for our sins. The next two verses, however, apply only to David, who had behaved foolishly and had fallen into sin. He prays that he will not be a stumbling block to others (69:5-6).
The reproach that David experienced foreshadowed the reproach of the Son of David, Jesus Christ, and it was for the sake of righteousness: "the reproaches of those who reproach You have fallen on me" (69:9, 10, 20; Romans 15:3). Those who are against God will naturally be against the righteous who serve God. David's zeal, like the zeal of Jesus for the House of God and true worship of God, angered those who were more liberal or secular (69:9; John 2:17). Just as David had become a byword and was shunned by his own people and even his family members, so it was with Jesus (69:8; John 1:11; 7:5; Mark 3:21). David spoke poetically in saying he was given vinegar and gall, meaning he was treated with contempt and bitterness, but this was literally fulfilled with Jesus (69:21; Matthew 27:34, 48). David's reaction to his enemies, however, is in sharp contrast to that of Jesus (69:22-28). David himself had confessed that the mercy of God far exceeds the mercy of man (2 Samuel 24:14). David had prayed that his enemies be destroyed without forgiveness, but Jesus prayed for God to forgive His enemies (Luke 23:34).
With expectancy, David prayed for the Lord's salvation and his own restoration, which would cause others who were righteous to rejoice, just as the righteous, who love the name of Jesus, rejoice at His resurrection and enthronement. The prayers of the meek (poor) shall be heard; their hearts shall live (eternally), and they shall dwell in the heavenly Jerusalem to praise Him forever (69:29-36).
Originally, Psalm 70 & 71 may have been one single psalm. With the exception of a few minor variations, Psalm 70 is the same as Psalm 40:13-17. The psalmist, David, likely made use of his earlier composition and altered it for a specific occasion and purpose. David is aware of his own inadequacy to help himself out of a desparate situation. He describes himself as "poor and needy" (70:5). As a prosperous king, he certainly did not lack in anything, but he lacked the ability to save himself. All his life he had trusted in God for deliverance and magnified the Lord in all situations, and now is no exception. He has a source of strength that is far greater than himself, so he calls upon God — his only help in trouble.
In Psalm 71, we read of David's familiar request that he not be put to shame. Why was David always so concerned that he not be ashamed by seeing defeat? It was not so much for himself, but for the sake of God, since, as a righteous king, David was God's representative. If he was put to shame, it would reflect badly upon the Lord, but David sought to always glorify the Lord. Upon being delivered, David would publicly worship God and give God all the credit, as he had done numerous times over the years. In such a way God would be glorified. David also repeatedly prayed for his enemies to be put to shame and suffer in a state of confusion, so that none of their schemes would work against him (70:2; 71:13); for that too would bring glory to God, since they were against God, and it would show that the righteous side was victorious. At the close of this psalm, David joyously praises God for answering his prayers (71:24).
David was quite old at the time of writing this psalm, and he had known much adversity during his life, yet since his childhood, he maintained a close relationship with God, and now that he is near the end of his life, he is even closer to God. He declares that since his birth God had upheld him (71:6) and taught him (71:17), and all his life he had declared God's wonderous works and goodness. Now that he is old, he resolves to do the same, as well as to praise God more and more and continually hope in Him (71:14). He prays that God would grant him a long enough life to teach the present generation all that God had taught him, and to tell them of God's power, strength, and righteousness (71:18-19). David is determined to make his latter years very productive in God's service, and with faith believing, he proclaims that God will revive him, restore his honour, and give him comfort so that he might continue to sing praises to God and witness to others about God's righteousness all day long (71:20-24).