Before Ephraim and Benjamin and Manasseh. "Ephraim" and "Manasseh" form a natural expansion of the "Joseph" of the preceding verse; but it is difficult to understand the mention of "Benjamin" here. Hengstenberg suggests, and both Canon Cook and Professor Cheyne seem to accept the suggestion, that it was only a small portion of Benjamin which adhered to Judah at the division of the kingdoms, the greater part attaching itself to the rival power.
Stir up thy strength; i.e. "rouse thyself from thine inaction—come forward, and make thy might to appear." And come and save us; literally, come for salvation to us. The writer identifies himself with the rebel tribes, who, after all, are a part of God's people—a part of Israel.