Judges 7:4-7

Then YAHWEH spoke to Gideon again, “You still have too many men. Take them down to the water, and I will test them for you there. If I tell you a man should go with you, he will go. If I tell you a man should not go with you, he will not go.” So Gideon brought the soldiers down to the water, and YAHWEH said to him, “Separate those who drink from their cupped hands and drink as a dog laps from those who kneel down to drink.” Of the ten thousand men, only three hundred lapped water from their cupped hands; all the others knelt to drink. Then YAHWEH told Gideon, “I will give you victory over the Midianites with the three hundred men who cupped their hands and drank. Tell everyone else to go home.”