The Psalm shows that in reading the Bible we have to distinguish between literal statements and figures of speech. We do this every day in our ordinary speaking, and we should understand the Bible in the same way. For example, “The statutes of the LORD are right” is literal; but stars is figurative. In particular, Jesus is here represented figuratively not only as the sun but also as a bridegroom and as a strong man. These figures and others are consistently applied to Jesus in the scriptures to express God’s purpose in him, e.g. he is the man God made strong for himself to achieve his great and glorious purpose with mankind; and his disciples are commanded to wait for his coming as a bride waits for the bridegroom when all the rejoicing will begin.
The quotation of verse 4 by the Apostle Paul, Romans 10:17-18,Waiting for response for Romans 10:17-18 shows the firmament here is the new heavens and that the luminaries are the disciples of Christ. They “declare the glory of God” and “their line/sound is gone out through all the earth, and their words to the end of the world.” vs.1-4.Waiting for response for Psalms 19:1-4 In these heavens there is an even greater luminary – the sun – the Lord Jesus Christ who as a bridegroom will come out of his chamber, rejoicing as a strong man to run a race” and “nothing will be heat from the heat” of his beams.
The rest of the Psalm extols the law of God and its application throughout all the Earth when his Son rules the world in righteousness, with a warning to his servants to keep his statutes and avoid presumptuous sins, in the hope of of "being acceptable in his sight" and receiving "the great reward". vs.11-14.Waiting for response for Psalms 19:11-14
This Psalm, like so much of the scriptures, looks forward to the time when God will replace the existing governments of the world with rulers who will confer righteousness, justice, and peace on mankind. This change of government is expressed by metaphor, as the Apostle Peter does here: “We, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness” (2 Peter 3:13).Waiting for response for 2 Peter 3:13 It is of this elevation of righteous rulers to high places in world government that the Psalm speaks: “The heavens declare the glory of God”, and the stars of this new world order will publish the knowledge of God throughout all the world: “There is no speech nor language, where their voice is not heard. Their line [rule] is gone through all the earth, and their words to the end of the world”. These words are quoted in the New Testament (Romans 10:18)Waiting for response for Romans 10:18 and applied to the preaching of the gospel by the Apostles, which shows that God is speaking in this Psalm, not only of the stars in the natural heavens, but also of those men are women who will be the stars of his new constitution for "they that turn many to righteousness shall shine as the stars for ever and ever" (Daniel 13:3).Waiting for response for Daniel 13:3
The greatest luminary in our sky is the sun and this is used to represent the Lord Jesus Christ who, as the chief ruler, will arise with healing in his beams to bless all nations. This Psalm tells us of the universal rulership of Christ, for as the sun: “His going forth is from the end of the heaven, and his circuit unto the ends of it; and there is nothing hid from the heat thereof”.
This Psalm extols the word of God.
This Psalm tells us there is great advantage to ourselves in obeying God’s commandments: “In keeping of them is great reward”, and so much of the Bible is about this great reward. By reading it for yourself you will learn what this reward is and come to appreciate that the things promised are of greater value than anything else in life, e.g. “More to be desired are they than gold, yea, than much fine gold”.
This Psalm is an excellent example of the character of the whole Word of God. It expresses the purpose of God to intervene in the affairs of the world and to institute righteous rule for all nations who will learn the truth about God and enjoy great blessings. It shows that God’s purpose is centred in his son Jesus Christ, and considerable information is given in the Old Testament about his life and work, written hundreds of years before he was born. Only God, with his foreknowledge, is able to do this; providing overwhelming evidence that the Bible is his word.