The angel of Yahweh came, and sat under the oak which was in Ophrah, that pertained to Joash the Abiezrite: and his son Gideon was beating out wheat in the winepress, to hide it from the Midianites.
Having at this point in the theophany recognized that it was a Divine Person who visited him, Gideon desired to worship Him, and he sought and received permission to take time to prepare the offering.  The Angel of Jehovah promised to wait until he returned.