What does Judges 6:11 mean?

Then the angel of the Lord came and sat under the oak tree at Ophrah, which belonged to Joash the Abiezrite. Gideon, Joash's son, was threshing wheat in a winepress to hide it from the Midianites. Judges 6:11 - Modern Text Bible

(Gideon is introduced, hiding his work to avoid the enemy. The setting is humble and fearful.)