Isaiah 21:4 - Matthew Poole's English Annotations on the Holy Bible

The night of my pleasure; the night, in which I used to have a sweet repose and sleep. He seems to have had this vision in a night. But withal this horror of the prophet by night was typical, and did signify that grievous horror and destruction which should befall the Babylonians in a night of great feasting and jollity, as it did, Daniel 5:1,30. Hath he, God, who showed him that vision, turned into fear unto me; into a time and matter of fear.