Gideon dared not place himself at the head of the army without still further evidence that God had called him to his work, and that He would be with him. He prayed, "If Thou wilt save Israel by mine hand, as Thou hast said, behold, I will put a fleece of wool in the floor; and if the dew be on the fleece only, and it be dry upon all the earth besides, then shall I know that Thou wilt save Israel by mine hand, as Thou hast said." In the morning the fleece was wet, while the ground was dry. But now a doubt arose, since wool naturally absorbs moisture when there is any in the air; the test might not be decisive. Hence he asked that the sign be reversed, pleading that his extreme caution might not displease the Lord. His request was granted.

Gideon turde ikke lede hæren, før han havde fået endnu en bekræftelse på, at Gud havde kaldet ham til denne opgave og ville være med ham. Han bad: "Hvis du vil frelse Israel ved min hånd, som du har lovet, så lægger jeg nu dette fåreskind på tærskepladsen, og falder der så dug alene på skindet, mens jorden ellers bliver ved at være tør, da ved jeg, at du vil frelse Israel ved min hånd, som du har lovet."