What does Judges 6:12 mean?

I delivered you out of the hand of the Egyptians, and out of the hand of all who oppressed you, and drove them out from before you, and gave you their land.

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.’”

Yahweh’s angel came, and sat under the oak which was in Ophrah, that belonged to Joash the Abiezrite. His son Gideon was beating out wheat in the wine press, to hide it from the Midianites.

Gideon said to him, “Oh, my lord, if Yahweh is with us, why then has all this happened to us? Where are all his wondrous works which our fathers told us of, saying, ‘Didn’t Yahweh bring us up from Egypt?’ But now Yahweh has cast us off, and delivered us into the hand of Midian.”

Yahweh looked at him, and said, “Go in this your might, and save Israel from the hand of Midian. Haven’t I sent you?”

He said to him, “O Lord, how shall I save Israel? Behold, my family is the poorest in Manasseh, and I am the least in my father’s house.”