What does 1 Kings 2:39 mean?

But after three years, two of Shimei's slaves ran away to Achish son of Maacah, king of Gath. When Shimei heard they were in Gath, he saddled his donkey and went there to get them back. 1 Kings 2:39 - Modern Text Bible

(After years of obedience, Shimei breaks Solomon's rule by leaving Jerusalem to retrieve his runaway slaves, setting up the consequences Solomon warned about.)