David wanted to know how strong he was. Therefore, he ordered Joab to take a census of the size of the army of Israel,

Nevertheless the king’s word prevailed against Joab [Who objected to the census]. Therefore Joab departed and went throughout all Israel and came to Jerusalem. Then Joab gave the sum of the number of the people to David. All Israel had one million one hundred thousand men who drew the sword, and Judah had four hundred and seventy thousand men who drew the sword. But he did not count Levi and Benjamin among them, for the king’s word was abominable to Joab (1 Chronicles 21:4–6).

Nine of the tribes of Israel numbered 1.1 million, and Judah numbered 470,000, but Joab found it distasteful to continue and so he did not count Levi and Benjamin.

Israel had a huge army, but David made a grievous error for thinking his strength was in his numbers, for even he himself should have remembered his battle against Goliath, and that would have reminded David that his strength was in the Lord.

Where is your strength?