Judges 7:5-8 - With three hundred men I will save you

7:5,6

The remaining soldiers were taken down to the water and they drank. Those who cupped their hands to drink were retained, those who lapped the water like a dog were sent home. It is often suggested that those who cupped their hands were more ready to deal with a sudden attack, while those who lapped were more vulnerable. However, this may be true, but there are no absolute grounds for accepting this. It may just have been a way of drastically thinning the numbers, and that is all the Bible is concerned with.

7:7,8

God then tells Gideon that He will save Israel with the three hundred. Note that in reality God did not need any of the three hundred, but He involves us in what He is doing, and He wants us to walk in fellowship with Him. So the bulk of the army was sent home, and the remaining three hundred took up their trumpets and provisions. Note that it seems that they did not have much, if anything, in the way of swords!