They rose early in the morning, and went out into the wilderness of Tekoa. As they went out, Jehoshaphat stood and said, “Listen to me, Judah, and you inhabitants of Jerusalem! Believe in Yahweh your God, so you will be established! Believe his prophets, so you will prosper.”
2 Chronicles 20:18 Jehoshaphat bowed his head with his face to the ground; and all Judah and the inhabitants of Jerusalem fell down before Yahweh, worshiping Yahweh.
2 Chronicles 20:19 The Levites, of the children of the Kohathites and of the children of the Korahites, stood up to praise Yahweh, the God of Israel, with an exceeding loud voice.
2 Chronicles 20:20 They rose early in the morning, and went out into the wilderness of Tekoa. As they went out, Jehoshaphat stood and said, “Listen to me, Judah, and you inhabitants of Jerusalem! Believe in Yahweh your God, so you will be established! Believe his prophets, so you will prosper.”
2 Chronicles 20:21 When he had taken counsel with the people, he appointed those who were to sing to Yahweh, and give praise in holy array, as they go out before the army, and say, “Give thanks to Yahweh; for his loving kindness endures forever.”
2 Chronicles 20:22 When they began to sing and to praise, Yahweh set ambushers against the children of Ammon, Moab, and Mount Seir, who had come against Judah; and they were struck.
The verse centers on "rose", "early", "morning", "went", "wilderness", "tekoa", and "jehoshaphat". It is saying that the verse draws attention to "rose" and "early", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 19's "The Levites of the children of the..." into verse 21's "When he had taken counsel with the...", so "rose" and "early" 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 "rose" and "early" with trust shaped by these words, not by a vague optimism outside the passage.