And God did so that night: for it was dry upon the fleece only, and there was dew on all the ground.
All Commentaries on Judges 6:40 Go To Judges 6
Ambrose of Milan
AD 397
Nor was it without a reason that he put the fleece neither in a field nor in a meadow, but in a threshing floor, where the harvest of the wheat is: “For the harvest is plenteous, but the laborers are few;” because, through faith in the Lord, there was about to be a harvest fruitful in virtues.