Judges 6:33-40
33 Now all the Midianites, Amalekites and other eastern peoples joined forces and crossed over the Jordan and camped in the Valley of Jezreel. 34 Then the Spirit of the Lord came on Gideon, and he blew a trumpet, summoning the Abiezrites to follow him. 35 He sent messengers throughout Manasseh, calling them to arms, and also into Asher, Zebulun and Naphtali, so that they too went up to meet them.
36 Gideon said to God, “If you will save Israel by my hand as you have promised— 37 look, I will place a wool fleece on the threshing floor. If there is dew only on the fleece and all the ground is dry, then I will know that you will save Israel by my hand, as you said.” 38 And that is what happened. Gideon rose early the next day; he squeezed the fleece and wrung out the dew—a bowlful of water.
39 Then Gideon said to God, “Do not be angry with me. Let me make just one more request. Allow me one more test with the fleece, but this time make the fleece dry and let the ground be covered with dew.” 40 That night God did so. Only the fleece was dry; all the ground was covered with dew.