Judg 6:37

הִנֵּ֣ה אָנֹכִ֗י מַצִּ֛יג אֶת־גִּזַּ֥ת הַצֶּ֖מֶר בַּגֹּ֑רֶן אִ֡ם טַל֩ יִהְיֶ֨ה עַֽל־הַגִּזָּ֜ה לְבַדָּ֗הּ וְעַל־כָּל־הָאָ֨רֶץ֙ חֹ֔רֶב וְיָדַעְתִּ֗י כִּֽי־תוֹשִׁ֧יעַ בְּיָדִ֛י אֶת־יִשְׂרָאֵ֖ל כַּאֲשֶׁ֥ר דִּבַּֽרְתָּ׃

then behold, I will place a fleece of wool on the threshing floor. If there is dew only on the fleece and all the ground is dry, then I will know that You are going to save Israel by my hand, as You have said.”