Whistling
Archimandrite Nikifor’s Biblical Encyclopedia
—a sound that can express derision, astonishment, or summons. Ruined Jerusalem and other judged cities become objects at which passersby hiss or whistle in horror and mockery (1 Kings 9:8; Jer. 19:8; 49:17). In Isaiah 5:26 the LORD whistles for distant nations, summoning them swiftly as agents of judgment. The meaning therefore depends on context; the sound itself is not assigned one fixed moral value.