Judges 6:36-38

Then Gideon said to God, “If You are going to rescue Israel through me, as You have spoken, behold, I will put a fleece of [freshly sheared] wool on the threshing floor. If there is dew only on the fleece, and it is dry on all the ground [around it], then I will know that You will rescue Israel through me, as You have said.” And it was so. When he got up early the next morning and squeezed the dew out of the fleece, he wrung from it a bowl full of water.