'Day and Night' in the Bible

But his delight is in the law of the LORD, and in his law will he exercise himself, day and night.

For thy hand is heavy upon me both day and night, and my moisture is like the drought in Summer. Selah.

My tears have been my meat day and night, while they daily say unto me, "Where is now thy God?"

This goeth day and night about the walls; mischief and vice are in the midst of it.

{A Psalm and song of the sons of Korah, to the Chanter upon Mahalath, to give thanks, an Instruction of Heman the Ezrahite} O LORD God my Savior, I have cried day and night before thee;