Utterly destroy - Rather, “devote to destruction” (Leviticus 27:28 note). When a city or people were thus made cherem, everything living was to be destroyed, and no part of the spoil fall to the conquerors (compare 1 Samuel 15:21). The valuables were put into the sacred treasury.
Related Commentaries of 1 Samuel 15:3
1 Samuel 15:3
3 Now go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass.