Part First.
The praise of the Divine glory in the natural world of creation is first general (vers. 1-4) and then particular (vers. 4-6).
I. The whole visible expanse of sky is the theme or occasion of praise. Its teaching or testimony is (1) constant and continuous, (2) independent of language, and (3) universal.
II. The commission given generally to the heavens to declare God's glory and to the firmament to show His handiwork is centred in the particular ascendency and sovereignty of the orb of day. (1) He has a position which implies supremacy. (2) The bright and radiant bravery of the sun is illustrated by significant comparisons. (3) The two leading features of his supremacy are clearly indicated: the wide sweep of his command and the penetrating, all-searching potency of his beams.
Part Second.
The transition from the natural world to the spiritual is made with startling abruptness. As in the stroke of a magic wand, the sun is gone. Another sun breaks forth from a higher heaven the law of the Lord.
I. This sudden substitution implies similarity or analogy. (1) The law of the Lord has a fixed position; (2) a resplendent beauty and authoritative power; (3) a sweep and range to take in the uttermost bounds of human consciousness and experience, as well as a piercing, fiery energy to ransack every nook and cranny in the thoughts and intents of the human heart.
II. In this great analogy a difference is to be noted. The heavens are the result in time of what God, as the Almighty, is pleased from all eternity to determine fully to do; the law is the image from everlasting to everlasting of what God, as Jehovah, from everlasting to everlasting necessarily is. And as what God in His essential nature is transcends incalculably in glory what God, in the exercise of His discretionary choice, may think fit to do, so the law of Jehovah transcends the heavens which declare His glory, and in which He has set a tabernacle for the sun.
R. S. Candlish, The Gospel of Forgiveness,p. 113.
References: Psalms 19:2. A. Mursell, Christian World Pulpit,vol. xix., p. 147. Psalms 19:3. Preacher's Monthly,vol. iv., p. 249. Psalms 19:3; Psalms 19:4. V. Welby Gregory, Expositor,3rd series, vol. iii., p. 315.Psalms 19:4. W. G. Harder, Christian World Pulpit,vol. vi., p. 398; H. R. Reynolds, Notes of the Christian Life,p. 146. Psalms 19:4-6. Spurgeon, Sermons,vol. xvii., No. 1020; A. P. Stanley, Sermons in the East,p. 71.