and they encamped against them, and destroyed the increase of the earth, until you come to Gaza, and left no sustenance in Israel, neither sheep, nor ox, nor donkey.
The Amalekites and other tribes that lived in the Arabian Desert east of Canaan joined the Midianites in their raids. These desert-dwellers were the "sons of the east" (Judges 6:3). The raids extended all the way to Gaza on the Mediterranean coast (Judges 6:4), far into Israel.