Psalms 136:7

7.Who made the great lights, etc. — Moses calls the sun and moon the two great lights, and there is little doubt that the Psalmist here borrows the same phraseology. What is immediately added about the stars, is, as it were, accessory to the others. It is true, that the other planets are larger than the moon, but it is stated as second in order on account of its visible effects. The Holy Spirit had no intention to teach astronomy; and, in proposing instruction meant to be common to the simplest and most uneducated persons, he made use by Moses and the other Prophets of popular language, that none might shelter himself under the pretext of obscurity, as we will see men sometimes very readily pretended an incapacity to understand, when anything deep or recondite is submitted to their notice. Accordingly, as Saturn though bigger than the moon is not so to the eye owing to his greater distance, the Holy Spirit would rather speak childishly than unintelligibly to the humble and unlearned. The same remark may be made upon what the Psalmist adds regarding God’s having assigned the sun and moon their respective parts, making the one to rule the day, and the other to rule the night, by which we are not to understand that they exercise any government, but that the administrative power of God is very manifest in this distribution. The sun in illuminating the earth through the day, and the, moon and stars by night, may be said to yield a reverential homage to God.