From H7043 (qalal, to be light/swift). Describes swiftness of movement — light-footedness, speed, agility. Used of warriors, horses, clouds, and the fleeting nature of human life. The word carries both positive (military prowess) and negative (life's brevity) connotations.
Job uses qal to lament the swiftness of human life: 'My days are swifter than a weaver's shuttle' (Job 7:6). Isaiah 19:1 depicts the LORD riding upon a qal cloud — swift, unstoppable, arriving in judgment before anyone can prepare. The theological lesson is twofold: life is brief (so live with urgency), and God's judgment is swift (so live with reverence). The 'swift' nature of divine action contrasts with human impatience — God may seem slow to us, but when He moves, He moves with devastating speed.