"The people on the mount prostrate themselves in awe before the unseen God. They dare not continue to look upon the Heaven-sent fire. They fear that they themselves will be consumed; and, convicted of their duty to acknowledge the God of Elijah as the God of their fathers, to whom they owe allegiance, they cry out together as with one voice, “The Lord, He is the God; the Lord, He is the God.” With startling distinctness the cry resounds over the mountain and echoes in the plain below. At last Israel is aroused, undeceived, penitent. At last the people see how greatly they have dishonored God. The character of Baal worship, in contrast with the reasonable service required by the true God, stands fully revealed. The people recognize God's justice and mercy in withholding the dew and the rain until they have been brought to confess His name. They are ready now to admit that the God of Elijah is above every idol. PK 153.1"
"And when all the people saw it, they fell on their faces: and they said, The Lord, he is the God; the Lord, he is the God."
EGW directly quotes and describes the people's reaction in 1 Kings 18:39.
"The priests of Baal witness with consternation the wonderful revelation of Jehovah's power. Yet even in their discomfiture and in the presence of divine glory, they refuse to repent of their evil-doing. They would still remain the prophets of Baal. Thus they showed themselves ripe for destruction. That repentant Israel may be protected from the allurements of those who have taught them to worship Baal, Elijah is directed by the Lord to destroy these false teachers. The anger of the people has already been aroused against the leaders in transgression; and when Elijah gives the command, “Take the prophets of Baal; let not one of them escape,” they are ready to obey. They seize the priests, and take them to the brook Kishon, and there, before the close of the day that marked the beginning of decided reform, the ministers of Baal are slain. Not one is permitted to live. PK 153.2"
"And that prophet, or that dreamer of dreams, shall be put to death; because he hath spoken to turn you away from the Lord your God, which brought you out of the land of Egypt, and redeemed you out of the house of bondage, to thrust thee out of the way which the Lord thy God commanded thee to walk in. So shalt thou put the evil away from the midst of thee."
EGW connects the execution of the prophets of Baal to the Deuteronomic principle of removing false prophets who lead people astray. While not a direct quote, the action aligns with the principle.