"And the Lord will create upon every dwelling place of mount Zion, and upon her assemblies, a cloud and smoke by day, and the shining of a flaming fire by night: for upon all the glory shall be a defence."
EGW directly quotes Isaiah 4:5.
"Across a dreary, desertlike expanse they journeyed. Already they began to wonder whither their course would lead; they were becoming weary with the toilsome way, and in some hearts began to arise a fear of pursuit by the Egyptians. But the cloud went forward, and they followed. And now the Lord directed Moses to turn aside into a rocky defile, and encamp beside the sea. It was revealed to him that Pharaoh would pursue them, but that God would be honored in their deliverance. PP 283.2"
"And the Lord went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night:"
Both passages describe the Israelites' journey led by a cloud (or pillar of cloud), and the initial uncertainty and potential fear associated with the journey. EGW's passage expands on the details of the journey and the fear of pursuit, while Exodus 13:21 simply states the presence of the cloud. The connection is thematic and meaningful.
"Speak unto the children of Israel, that they turn and encamp before Pi–hahiroth, between Migdol and the sea, over against Baal–zephon: before it shall ye encamp by the sea."
EGW describes God directing Moses to encamp by the sea, which is directly mentioned in Exodus 14:2. She adds details about the rocky defile, which is an interpretation of the geographical location.
"In Egypt the report was spread that the children of Israel, instead of tarrying to worship in the desert, were pressing on toward the Red Sea. Pharaoh's counselors declared to the king that their bondmen had fled, never to return. The people deplored their folly in attributing the death of the first-born to the power of God. Their great men, recovering from their fears, accounted for the plagues as the result of natural causes. “Why have we done this, that we have let Israel go from serving us?” was the bitter cry. PP 283.3"
"And it was told the king of Egypt that the people fled: and the heart of Pharaoh and of his servants was turned against the people, and they said, Why have we done this, that we have let Israel go from serving us?"
The EGW passage directly quotes and expands upon the sentiment expressed in Exodus 14:5 regarding Pharaoh's regret at letting Israel go.
"Pharaoh collected his forces, “six hundred chosen chariots, and all the chariots of Egypt,” horsemen, captains, and foot soldiers. The king himself, attended by the great men of his realm, headed the attacking army. To secure the favor of the gods, and thus ensure the success of their undertaking, the priests also accompanied them. The king was resolved to intimidate the Israelites by a grand display of his power. The Egyptians feared lest their forced submission to the God of Israel should subject them to the derision of other nations; but if they should now go forth with a great show of power and bring back the fugitives, they would redeem their glory, as well as recover the services of their bondmen. PP 283.4"
"And he took six hundred chosen chariots, and all the chariots of Egypt, and captains over every one of them."
The EGW passage directly references the specific number of chariots mentioned in Exodus 14:7 and elaborates on the context of Pharaoh's pursuit.
"And he made ready his chariot, and took his people with him:"
Both passages describe Pharaoh preparing his forces, but EGW provides more detail and interpretation. It's not a direct quote, but a thematic expansion.