What does Psalms Chapter 18 say, and which statements belong to its speaker?

The Latin incipit is Coeli enarrant. The separate heading describes God's glory shown by His works and His law's excellence and desirability. The inscription is unto the end, for David. The psalm says heavens show God's glory and the firmament His hands' work. Day utters speech to day and night knowledge to night; there are no speeches or languages where their voices are not heard. Their sound goes through earth and words to the world's ends. God set His tabernacle in the sun. It is like a bridegroom from a chamber and a giant rejoicing to run, with its circuit from heaven's end to the other and nothing hidden from its heat.

The Lord's unspotted law converts souls, faithful testimony gives wisdom to little ones, right justices rejoice hearts and a lightsome commandment enlightens eyes. Holy fear endures forever and judgments are true and justified, desirable above gold and many precious stones, sweeter than honey and honeycomb. The servant keeps them with great reward.

The speaker asks who understands sins and requests cleansing of secret ones and sparing from those of others. If these do not have dominion, he will be spotless and cleansed from the greatest sin. He hopes his words may please God and says his heart's meditation is always in His sight, addressing Him as helper and redeemer. The admitted wording does not substitute presumptuous sins for those of others.