# So Midian was subdued before the people of Israel

"So Yahweh subdued the Midianites before the people of Israel" or "So Yahweh helped the Israelites defeat the Midianites"

# they did not raise their heads up again

"they did not attack Israel again" 

# So the land had peace

"So the Israelites lived peacefully" 

# in the days of Gideon

"during the life of Gideon"