Judah was prosperous during the time of Northern Israel’s downfall (721 B.C.). Isaiah is speaking of what will happen in the future. The taking away of the staff of bread (the staff of life—the KJV says stay of bread), and the stay of water (v. 2) seems to describe her economic prosperity. It may be describing her fall in 589 B.C. (Book of Mormon dating), or it may be speaking of the time period following Christ’s ministry among them in the flesh (A.D. 31–33). Perhaps it is a dual prophecy; it certainly fits both time periods.
Judah’s blessing among the tribes of Israel was to be the political leader. “The sceptre shall not depart from Judah, nor a lawgiver from between his feet, until Shiloh come; and unto him shall the gathering of the people be” (Genesis 49:10). This blessing was also to be lost and was lost in both of the above time periods. The various leadership roles are mentioned in verses two and three. The loss will extend to their spiritual leaders as well, the prophet and the ancient (patriarch) (see 2 Nephi 19:15–16).