Judges 7:5-7

So he brought the people down to the water. And the LORD said to Gideon, “Every one who laps the water with his tongue, as a dog laps, you shall set by himself. Likewise, every one who kneels down to drink.” And the number of those who lapped, putting their hands to their mouths, was 300 men, but all the rest of the people knelt down to drink water. And the LORD said to Gideon, “With the 300 men who lapped I will save you and give the Midianites into your hand, and let all the others go every man to his home.”