Judges 6:36-38
And Gideon said unto God, 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 beside, then shall I know
that thou wilt save Israel by mine hand, as thou hast said.
And
it was so: for he rose up early on the morrow, and thrust the fleece
together, and wringed the dew out of the fleece, a bowl full of water.