12. thoughts of the Lord--Their unsearchable wisdom, overruling seeming disaster to the final good of His people, is the very ground on which the restoration of Israel hereafter (of which the restoration from Babylon is a type) is based in Isa 55:8; compare with Mic 4:3, 12, 13, which prove that Israel, not merely the Christian Church, is the ultimate subject of the prophecy; also in Ro 11:13. God's counsel is to discipline His people for a time with the foe as a scourge; and then to destroy the foe by the hands of His people.
      gather them as . . . sheaves--them who "gathered" themselves for Zion's destruction (Mic 4:11) the Lord "shall gather" for destruction by Zion (Mic 4:13), like sheaves gathered to be threshed (compare Isa 21:10; Jer 51:33). The Hebrew is singular, "sheaf." However great the numbers of the foe, they are all but as one sheaf ready to be threshed [CALVIN]. Threshing was done by treading with the feet: hence the propriety of the image for treading under foot and breaking asunder the foe.

JFB.