2 Chronicles 11:16
And after them out of all the tribes of Israel such as set their hearts to seek the LORD God of Israel came to Jerusalem, to sacrifice unto the LORD God of their fathers. And after them out of all the tribes of Israel such as set their hearts to seek the LORD God of Israel came to Jerusalem, to sacrifice unto the LORD God of their fathers.
After the division of the kingdom, those out of all the tribes of Israel who set their hearts to seek the Lord God of Israel came to Jerusalem to sacrifice to the Lord God of their fathers. They came from every tribe, drawn by a fixed purpose to worship Him rather than to accept the altered worship in the north.
Their arrival strengthened the kingdom of Judah and made Rehoboam strong for three years. During that time the people walked in the way of David and Solomon, holding to the true worship and obedience that had marked the best years of the united kingdom. Judah's strength and early prosperity under Rehoboam came not from defenses and fortified cities but from devotion to God and recognizing Him as supreme ruler.