Charles H. Spurgeon on Psalms 19:2

"Day unto day uttereth speech, and night unto night sheweth knowledge." As if one day took up the story where the other left it, and each night passed over the wondrous tale to the next. The original has in it the thought of pouring out or welling over, with speech; as though days and nights were but as a fountain flowing evermore with Jehovah's praise. Oh to drink often at the celestial well, and learn to utter the glory of God! The witnesses above cannot be slain or silenced; from their elevated seats they constantly preach the knowledge of God, unawed and unbiased by the judgment of men. Even the changes of alternating night and day are mutely eloquent, and light and shade equally reveal the Invisible One; let the vicissitudes of our circumstances do the same, and while we bless the God of our days of joy, let us also extol him who giveth "songs in the night."

The lesson of day and night is one which it were well if all men learned. It should be among our day-thoughts and night-thoughts, to remember the flight of time, the changeful character of earthly things, the brevity both of joy and sorrow, the preciousness of life, our utter powerlessness to recall the hours once flown, and the irresistible approach of eternity. Day bids us labour, night reminds us to prepare for our last hime; day bids us work for God,and night invites us to rest in him; day bids us look for endless day, and night warns us to escape from everlasting night.