Charles Ellicott Commentary Isaiah 21:4

"My heart fluttereth, horror hath affrighted me; the twilight that I desired hath been turned into trembling unto me." — Isaiah 21:4 (ASV)

The night of my pleasure ... —The words point to the prophet’s longing for the darkness of night, either as a time of rest from his labor, or, more probably, for contemplation and prayer (Psalms 119:148), and to the invasion of that rest by the vision of terror. The suggestion that the prophet speaks as identifying himself with the Babylonians, and refers to the capture of their city during a night of revelry (Daniel 5:1; Daniel 5:30; Herod., i. 121; Xenoph. Cyrop., vii. 23), is hardly tenable.