1st Samuel 17:41 And the Philistine came on and drew near unto David; and the man that bare the shield went before him. 42 And when the Philistine looked about, and saw David, he disdained him: for he was but a youth, and ruddy, and of a fair countenance.
1st Samuel 17:43 And the Philistine said unto David, Am I a dog, that you come to me with staves? And the Philistine cursed David by his gods. 45 Then said David to the Philistine, Thou comest to me with a sword, and with a spear, and with a shield: but I come to thee in the name of the Lord of hosts, the God of the armies of Israel, whom thou hast defied. 49 And David put his hand in his bag, and took thence a stone, and slang it, and smote the Philistine in his forehead, that the stone sunk into his forehead; and he fell upon his face to the earth.
Therefore, after many similar deliverances over the span of many years, for David to say go number the people, as if success was ever in numbers, caused God to be greatly displeased. Taking God’s glory, or credit to yourself is what had caused Moses and Aaron not to enter the promised land, for when they said angrily, “Must we fetch water” they gave the people the impression that the miraculous works of The Lord were to be attributed to themselves.
And that’s a huge problem, for if they could exercise miraculous power to bring forth water from the rock independent of God, then, the logical conclusion is that they inherently possess supernatural power, of their own, something which no created being must ever claim.
1st Samuel 17:50 So David prevailed over the Philistine with a sling and with a stone, and smote the Philistine, and slew him; but there was no sword in the hand of David.
May God add His blessing to the study of His word. “Good night” and God bless!