KOPH The psalmist shows his reliance on the Lord here with the "dawn to dusk" approach to seeking God, he seeks Him every waking hour "hoping in His words" and "meditating on His promise". I need to try not to seek the Lord only when it is convenient for me, but instead remember to seek Him in all those times in-between, for all sorts of reasons, not just in need.
PE God's words are the light in our darkness, and as complex as He is, they have been given to us in a way that we can understand. Praying to God to be merciful is something we all want God to grace us with, yet when we actually stop and think of the mercy and justice we have earned, it may be less appealing to think of what judgements we have brought upon ourselves.
SAMECH In the ESV translation it says "double-minded" instead of "vain". God doesn't want us to be luke-warm in our faith to Him (1 Kings 18:21, Rev 3:15-16). I heard a message recently that said this: "As a gardener you can't just love the flowers, you have to hate the weeds".
MEM The psalmist has devoted himself and his life to the study of God's word, it is the highest in his heart as we see the devotion and love he has for it. It is the sword and shield against those who come against him, as God will always get the upper hand, simply being an enemy of the psalmist is also being an enemy of God, not a wise choice.
Here is the Elevation Worship song mentioned in my Psalm 119 post about the unfailing and unchanging nature of God. The reason that we can trust in Him and rely on Him like we can never do without disappointment in people. https://www.youtube.com/watch?v=9gXrJtvpJXM
CAPH Despite not seeing an end to his suffering in sight "How many are my days?" (v.84) i.e., How long will I live like this. The psalmist is able to keep trust in the Lord, knowing that He is faithful, and will not provide greater challenge than we can face.
TETH The psalmist tells us that the negative situations he is facing are a good thing, they have given him the chance to learn about the grace and goodness of God. He is thankful that ill had befallen him – how many people outside of God can say the same? I love that God gives us situations that we can learn from.
ZAIN Despite, or perhaps because of negative things afflicting the psalmist, he turns his trust and hope towards God's word. The word of God brings him comfort and life when the world aims to deride and hurt him. There is a lot of emphasis being put on how we can look to God when trouble seeks us out, and not only find answers in his law, but comfort and life no matter what we are facing.
HE We see the psalmist again asking for understanding and showing his whole-hearted approach to God's word. There is a contrast to how the psalmist must feel when living off of God's path, as it is shown when he is on the right path he delights in it.
GIMEL Previously the psalmist meditated in God's precepts, here we see him meditating in God's statutes, and taking delight in doing God's will. He is counseled by God's testimony, meaning he uses the word of God as guidance for his life and takes joy in doing so, yet he is asking God to take this feeling further! He wants to look on God's word with a sense of wonder despite the hardships he has faced (v.23).