Rehoboam assembled an army to fight Israel, but the word of the LORD came through Shemaiah. The message said not to go up or fight their brothers, because the thing was from God, and they returned home (2 Chronicles 11:1-4).
In 2 Chronicles 11:1–4, Rehoboam gathers a large army from Judah and Benjamin to attack the northern tribes and restore his rule. Before the conflict begins, God’s message comes through Shemaiah, telling Rehoboam and the people not to fight “your brothers” but to go home. The stated reason is that the situation has come about under God’s direction. This scene follows the kingdom’s split after Solomon, when Rehoboam rules Judah while Jeroboam leads the northern tribes. The passage works like a short interruption: a military plan is announced, then immediately halted by a prophetic message.
The passage presents a clear collision between royal policy and prophetic speech. Rehoboam forms a concrete war plan: a large, selected force from Judah and Benjamin is gathered to fight the northern tribes and “bring the kingdom back” under his rule (explicit).
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with 2 Chronicles 11:1-4, then read the surrounding section so the answer stays connected to the passage's flow.
1When Rehoboam was come to Jerusalem, he assembled the house of Judah and Benjamin, one hundred eighty thousand chosen men, who were warriors, to fight against Israel, to bring the kingdom again to Rehoboam.
2But the word of Yahweh came to Shemaiah the man of God, saying,
3Speak to Rehoboam the son of Solomon, king of Judah, and to all Israel in Judah and Benjamin, saying,
4Thus says Yahweh, You shall not go up, nor fight against your brothers: return every man to his house; for this thing is of me. So they listened to the words of Yahweh, and returned from going against Jeroboam.