The author of the psalm is not identified, which means that we do not know who wrote it or when it was written. Yet we can see that his focus is on the mercy of God.
The psalmist begins by saying that he is in the depths, a graphic word picture of a man overwhelmed by powerful waters (vv. 1-2). The verb indicates that he has been there for a while, so this is the assessment of an experienced believer. There are several reasons why a believer could be in the depths: difficult providences in his personal life, denial of hopes that he may have anticipated, a sense of desertion by God. Yet such experiences are not the primary reasons for his despondency at the time. The psalmist’s mention of sin in verse 3 tells us what was the cause of his dejection.
Yet the psalmist knew where help was to be found – in the God against whom he had sinned. Therefore he turns to the Lord and asks for mercy. We should note his attitude as he draws near to God: there is a mixture of boldness (he asks the Lord to open his ears) and there is an expression of humility (he pleads for mercy). How can a sinner have such boldness in the presence of the holy God? The answer is that he knows the character and the promises of the God to whom he is speaking.
God’s mercy fills the psalmist with amazement (vv. 3-4). He knows that if the Lord treated him as he deserved he would have no expectation of help. Yet he knows about God’s desire to forgive. The apostle John tells us that God is forgiving, that he is faithful and just to forgive us our sins and cleanse us from all unrighteousness (1 John 1:9).
The psalmist then likens himself to the watchmen who stood on the walls of a city looking for the coming of daylight (vv. 5-6). This illustration tells us that there was expectancy of deliverance in his heart. The reason for his confidence was not in his earnest prayer but in the sure word of God. And his illustration of coming daylight depicts not partial release but complete release from the problem his sins have caused.
Out of his own experience, the psalmist was able to comfort others (vv. 7-8). We can say to one another, ‘Look what the Lord did for me. I know he can also do it for you.’ The psalmist’s words here are a reminder that although each Christian has an individual path, it is a similar path to other believers. Because he has been forgiven much and rescued from great danger, he understands the needs of every other believer, and he is sympathetic to them and confident about their deliverance and forgiveness as well.