The statement that they raised a clamor in the house of the LORD as on the day of festival,
means that after their victory, Israel’s enemies invaded the temple and raised their voices as if they were having a party. In God’s judgment he allowed a people who should not have entered the temple to enter it (see also Lamentations 1:10). Where God stopped the festivals of his people, he allowed the enemy to have their own sort of festival.1
7 The Lord has scorned his altar, disowned his sanctuary; he has delivered into the hand of the enemy the walls of her palaces; they raised a clamor in the house of the LORD as on the day of festival.