[8:7] 2 sn I will thresh. The metaphor is agricultural. Threshing was usually done on a hard threshing floor. As farm animals walked over the stalks, pulling behind them a board embedded with sharp stones, the stalks and grain would be separated. See O. Borowski, Agriculture in Iron Age Israel, 63-65. Gideon threatens to use thorns and briers on his sledge.
[8:7] 4 tn This is apparently a rare instrumental use of the Hebrew preposition אֵת (’et, note the use of ב [bet] in v. 16). Some, however, argue that אֵת more naturally indicates accompaniment (“together with”). In this case Gideon envisions threshing their skin along with thorns and briers, just as the stalks and grain are intermingled on the threshing floor. See C. F. Burney, Judges, 229-30.