A fleece is like a contract between you and the Lord! You make a bargain with God, you make Him an offer. You specify the kind of revelation you want.--Like Gideon did!
Gideon laid a fleece on the ground and said, "Now Lord, if the fleece is wet in the morning and all the ground's dry, then I'll know that such-and-such is Your Will!" But when the Lord did it he still wasn't sure, so the next evening he said, "Now Lord, if the fleece is dry and the ground is wet, I'll believe it!" So the Lord did it, and Gideon then knew that God was with him. If the Lord hadn't performed a miracle with the fleece, Gideon might have quit entirely and lost heart. But when the Lord answered, that certainly was a miracle! (Judges 6:36-40)
When the Lord answers a fleece, then you've got to have the faith that it was God, and that that's the right answer.--And when you make a deal with God, you'd better stick to it no matter what. It's just as important for you to keep your part of the bargain and keep your word as it is for God to keep His! It's a test of faith! So make a wise fleece, then stick to it, and you'll know it's God's answer!