Matthew Poole and continuators on Judges 8:28

28 ¶ Thus was Midian subdued before the children of Israel, so that they lifted up their head no more : and the countrey was in quietness forty years in the days of Gideon .

i. e. Recovered not their former Strength or Courage, so as to Conquer or Oppress others, as they had done.

i. e. To the fortieth year, from the beginning of the Midianitish Oppression; see on Iudg. 3. 11.

i. e. As long as Gideon lived.