Charles H. Spurgeon on Psalms 119:148

Mine eyes prevent the night watches. Or rather, the watches. Before the watchman cried the hour, he was crying to God. He did not need to be informed as to how the hours were flying, for every hour his heart was flying towards heaven. He began the day with prayer, and he continued in prayer through the watches of the day, and the watches of the night. The soldiers changed guard, but David did not change his holy occupation. Specially, however, at night did he keep his eyes open, and drive away sleep, that he might maintain communion with his God. He worshipped on from watch to watch as travellers journey from stage to stage.

That I might meditate in thy word. This had become meat and drink to him. Meditation was the food of his hope, and the solace of his sorrow: the one theme upon which his thoughts ran was that blessed "word" which he continually mentions, and in which his heart rejoices. He preferred study to slumber; and he learned to forego his necessary sleep for much more necessary devotion. It is instructive to find meditation so constantly connected with fervent prayer: it is the fuel which sustains the flame. How rare an article is it in these days.