The Hebrew verb qālaʿ (קָלַע) means to sling or throw with a sling, and in a secondary sense to carve or engrave (as in carving the walls of the temple). As a weapon technology, slinging involved whirling a leather strap with a stone and releasing it at high velocity — an ancient weapon of surprising effectiveness. Related nouns include qelaʿ (sling) and qallaʿ (slinger).
The theology of qālaʿ is inseparable from David's victory over Goliath (1 Samuel 17:49–50) — one of Scripture's defining illustrations that God's power is not dependent on conventional strength. David's sling and stone, wielded in the name of the LORD of Hosts, felled a giant that no armored warrior could defeat. This narrative is echoed throughout Scripture: the weak things of the world confound the mighty (1 Corinthians 1:27). The 700 left-handed Benjaminite slingers of Judges 20:16, 'each of whom could sling a stone at a hair and not miss,' shows the skill involved — yet it is always God who guides the stone.