Psalms 19:2

2.Day unto day uttereth speech. Philosophers, who have more penetration into those matters than others, understand how the stars are arranged in such beautiful order, that notwithstanding their immense number there is no confusion; but to the ignorant and unlettered, the continual succession of days is a more undoubted proof of the providence of God. David, therefore, having spoken of the heavens, does not here descend from them to other parts of the world; but, from an effect more sensible and nearer our apprehension, he confirms what he has just now said, namely, that the glory of God not only shines, but also resounds in the heavens. The words may be variously expounded, but the different expositions which have been given of them make little difference as to the sense. Some explain them thus, that no day passes in which God does not show some signal evidence of his power. Others are of opinion that they denote the augmentations of instruction and knowledge, - that every succeeding day contributes something new in proof of the existence and perfections of God. Others view them as meaning that the days and nights talk together, and reason concerning the glory of their Creator’, but this is a somewhat forced interpretation. David, I have no doubt, here teaches, from the established alternations of days and nights, that the course and revolutions of the sun, and moon, and stars, are regulated by the marvellous wisdom of God. Whether we translate the words Day after day, or one day to another day, is of little consequence; for all that David means is the beautiful arrangement of time which the succession of days and nights effects. If, indeed, we were as attentive as we ought to be, even one day would suffice to bear testimony to us of the glory of God, and even one night would be sufficient to perform to us the same office. But when we see the sun and the moon performing their daily revolutions, — the sun by day appearing over our heads, and the moon succeeding in its turns — the sun ascending by degrees, while at the same time he approaches nearer us, — and afterwards bending his course so as to depart from us by little and little; — and when we see that by this means the length of the days and nights is regulated, and that the variation of their length is arranged according to a law so uniform, as invariably to recur at the same points of time in every successive year, we have in this a much brighter testimony to the glory of God. David, therefore, with the highest reason, declares, that although God should not speak a single word to men, yet the orderly and useful succession of days and nights eloquently proclaims the glory of God, and that there is now left to men no pretext for ignorance; for since the days and nights perform towards us so well and so carefully the office of teachers, we may acquire, if we are duly attentive, a sufficient amount of knowledge under their tuition.