Passage
And when they were come to Jerusalem in the third month, in the fifteenth year of the reign of Asa,
And when they were come to Jerusalem in the third month, in the fifteenth year of the reign of Asa,
2 Chronicles 15:8 And when Asa had heard the words, and the prophecy of Azarias the son of Oded the prophet, he took courage, and took away the idols out of all the land of Juda, and out of Benjamin, and out of the cities of mount Ephraim, which he had taken, and he dedicated the altar of the Lord, which was before the porch of the Lord.
2 Chronicles 15:9 And he gathered together all Juda and Benjamin, and the strangers with them of Ephraim, and Manasses, and Simeon: for many were come over to him out of Israel, seeing that the Lord his God was with him.
2 Chronicles 15:10 And when they were come to Jerusalem in the third month, in the fifteenth year of the reign of Asa,
2 Chronicles 15:11 They sacrificed to the Lord in that day of the spoils, and of the prey, that they had brought, seven hundred oxen, and seven thousand rams.
2 Chronicles 15:12 And he went in to confirm as usual the covenant, that they should seek the Lord the God of their fathers with all their heart, and with all their soul.
The verse centers on "come", "jerusalem", "third", "month", "fifteenth", "year", and "reign". It is saying that the verse draws attention to "come" and "jerusalem", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 9's "And he gathered together all Juda and..." into verse 11's "They sacrificed to the Lord in that...", so "come" and "jerusalem" belong inside that flow. In 2 Chronicles context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "come" and "jerusalem" with trust shaped by these words, not by a vague optimism outside the passage.