Judges 6:3
And so it was, when Israel had sown, that the Midianites came up, and the Amalekites, and the children of the east, even they came up against them; And so it was, when Israel had sown, that the Midianites came up, and the Amalekites, and the children of the east, even they came up against them;
The attack came every year as soon as Israel had sown and as the harvests began to ripen. Those who came up were the Midianites from the eastern border of Canaan and the deserts beyond, together with the Amalekites from the south of Canaan and other peoples from the east. The Midianites had been nearly destroyed by Israel in the days of Moses but had since increased greatly and grown again into a numerous and powerful people thirsting for revenge.
The invasion was permitted because Israel did evil and the protecting hand of God was withdrawn. They chose ease and self-indulgence and let slip their opportunities for completing the conquest of the land. By mingling among the surrounding peoples, intermarrying with them, learning their practices, serving idols, and indulging appetite and passion, they were separated from God, His strength was removed from them, and they could no longer prevail against their enemies. Thus they were brought into subjection to the very nations they might through God have subdued.
The ravage fell first on the tribes east of the Jordan but spread over the whole land from the river Jordan to the Philistine plain. The wild, fierce desert dwellers came in overwhelming multitude like locusts, with their flocks and herds, and spread like a devouring plague. They stayed until the last fruits of the earth had been gathered, stripped the fields of their increase, robbed and mistreated the inhabitants, and then returned to the deserts. Israelites dwelling in the open country were forced to abandon their homes and crowd into walled towns, seek refuge in fortresses, and find shelter in caves and rocky strongholds among the mountains.
The oppression continued seven years, until in distress the people gave heed to the Lord's reproof and confessed their sins, when God raised up a helper for them. The episode is one instance of the repeated story of backsliding followed by chastisement and then confession and deliverance. God did not utterly forsake His people but preserved a remnant true to Him and raised up faithful and valiant men to put down idolatry and deliver them, although when the deliverer died the people returned to their idols.