Destroy — Both persons and goods, kill all that live, and consume all things without life, for I will have no name nor remnant of that people left, whom long since I have devoted to utter destruction. Spare not — Shew no compassion or favour to any of them. The same thing repeated to prevent mistake, and oblige Saul to the exact performance hereof. Slay, &c. — Which was not unjust, because God is the supreme Lord of life, and can require his own when he pleaseth; infants likewise are born in sin, and therefore liable to God's wrath. Their death also was rather a mercy than a curse, as being the occasion of preventing their sin and punishment. Ox, &c. — Which being all made for man's benefit, it is not strange if they suffer with him, for the instruction of mankind.
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.