and I said to you, I am Yahweh your God; you shall not fear the gods of the Amorites, in whose land you dwell. But you have not listened to my voice.
So here was Gideon hiding from the Midianites as he was threshing the wheat because if the Midianites had caught him they'd take the wheat. And so he was out by the winepress threshing wheat and here was an angel sitting under an oak tree.