"In another prophetic message, given “in the year that King Ahaz died,” the prophet had declared: “The Lord of hosts hath sworn, saying, Surely as I have thought, so shall it come to pass; and as I have purposed, so shall it stand: that I will break the Assyrian in My land, and upon My mountains tread him underfoot: then shall his yoke depart from off them, and his burden depart from off their shoulders. This is the purpose that is purposed upon the whole earth: and this is the hand that is stretched out upon all the nations. For the Lord of hosts hath purposed, and who shall disannul it? and His hand is stretched out, and who shall turn it back?” Isaiah 14:28, 24-27 . PK 350.1"
"The Lord of hosts hath sworn, saying, Surely as I have thought, so shall it come to pass; and as I have purposed, so shall it stand:"
EGW directly quotes Isaiah 14:24.
"The power of the oppressor was to be broken. Yet Hezekiah, in the earlier years of his reign, had continued to pay tribute to Assyria, in harmony with the agreement entered into by Ahaz. Meanwhile the king had taken “counsel with his princes and his mighty men,” and had done everything possible for the defense of his kingdom. He had made sure of a bountiful supply of water within the walls of Jerusalem, while without the city there should be a scarcity. “Also he strengthened himself, and built up all the wall that was broken, and raised it up to the towers, and another wall without, and repaired Millo in the city of David, and made darts and shields in abundance. And he set captains of war over the people.” 2 Chronicles 32:3, 5, 6 . Nothing had been left undone that could be done in preparation for a siege. PK 350.2"
"He took counsel with his princes and his mighty men to stop the waters of the fountains which were without the city: and they did help him. So there was gathered much people together, who stopped all the fountains, and the brook that ran through the midst of the land, saying, Why should the kings of Assyria come, and find much water? Also he strengthened himself, and built up all the wall that was broken, and raised it up to the towers, and another wall without, and repaired Millo in the city of David, and made darts and shields in abundance."
EGW directly quotes 2 Chronicles 32:3-5.