To the choirmaster. A Psalm of David.

The heavens declare the glory of God, and the sky above proclaims his handiwork.
Psalm 19:1

One look at creation and the psalmist makes a wonderful statement, that it declares the glory of God and it proclaims God's handiwork.

Day to day pours out speech, and night to night reveals knowledge.
There is no speech, nor are there words, whose voice is not heard.
Their voice goes out through all the earth, and their words to the end of the world. In them he has set a tent for the sun, which comes out like a bridegroom leaving his chamber, and, like a strong man, runs its course with joy.
Its rising is from the end of the heavens, and its circuit to the end of them, and there is nothing hidden from its heat.
v.2-6

But the psalmist goes on, and doesn't concentrate on the awesomeness of creation, no he concentrates on his Maker, God. He continues declaring what he delights in most about his Creator, His Word.

The law of the LORD is perfect, reviving the soul; the testimony of the LORD is sure, making wise the simple; the precepts of the LORD are right, rejoicing the heart; the commandment of the LORD is pure, enlightening the eyes; the fear of the LORD is clean, enduring forever; the rules of the LORD are true, and righteous altogether.
More to be desired are they than gold, even much fine gold; sweeter also than honey and drippings of the honeycomb.
Moreover, by them is your servant warned; in keeping them there is great reward.

v.7-11

David, after glorying in God through creation and then declaring the majesty of His law and recognizing that there is great reward in keeping them, looks within and asks the Lord for His grace, to keep him from presumptuous sins and its dominion over him. Finally he ends his praise with prayer, asking for God's approval of what he has just said.

Who can discern his errors? Declare me innocent from hidden faults.
Keep back your servant also from presumptuous sins; let them not have dominion over me! Then I shall be blameless, and innocent of great transgression.
Let the words of my mouth and the meditation of my heart be acceptable in your sight, O LORD, my rock and my redeemer.
v.12-14

Without trying to steer from the main point of this psalm, it strikes me how David in the last verse says: "Let the words of my mouth and the meditation of my heart be acceptable in your sight, O LORD, my rock and my redeemer."
After praising God and declaring the wonders of His law, he's so reverent to God that he asks the Lord's approval on his thoughts and words, he wants to make sure he's not offending God in any way. What a humbling request. Definitely something to ponder on for future prayers and praises to God.