Shofetim 6:1-2

Orthodox Jewish Bible

6 And the Bnei Yisroel did evil in the sight of Hashem; Hashem delivered them into the yad Midyan [See Gn.25:2] sheva shanim.

² And the yad Midyan prevailed against Yisroel; and because of Midyan the Bnei Yisroel made them dens in the mountains, and caves, and strongholds.