What does Isaiah 11:13 mean?
Around 930 BC, the Israelites divided into two nations. The northern nation was commonly called Israel or Ephraim, after its largest tribe. It consisted of the northern ten of the original twelve tribes. The nation of the southern two tribes was called Judah after the larger of the pair. Judah retained the capital of Jerusalem. Israel or Ephraim's capital was Samaria.The divided nations found themselves in regular conflict with each other. Already in this book, Isaiah has described Israel's partnership with Syria to attack Judah. Now, Isaiah is writing about the future kingdom of the Messiah when all the nations of the earth will willingly gather under His rule (Isaiah 11:10).
At that time, the Lord will also assemble the scattered Jewish people from the ends of the world to reunite under His rule from Mount Zion in Jerusalem (Isaiah 11:11–12). Isaiah says that when that happens, the division between the two nations of Israel will be ended. Ephraim will no longer be jealous of Judah. Judah will no longer harass Ephraim. In short, they will be united as one nation.