King David Takes a Census of Israel

As one of David's sinful acts, he took a census of Israel, essentially out of self pride. In those days, it was understood that one would only take a census of what or whom belonged to them. However, during this time of God's plan, Israel specifically belonged to God, not David. As a result, God judged Israel. 

Joab is the one who questioned (pushed back on) David, but had to follow his king's order. So, he carried out the census, leaving out the tribes of Levi and Benjamin, and came back with the numbers...

Israel - 1,100,000 men
Judah - 470,000 men