"Chapter 18—Preaching Among the Heathen This chapter is based on Acts 14:1-26 . From Antioch in Pisidia, Paul and Barnabas went to Iconium. In this place, as at Antioch, they began their labors in the synagogue of their own people. They met with marked success; “a great multitude both of the Jews and also of the Greeks believed.” But in Iconium, as in other places where the apostles labored, “the unbelieving Jews stirred up the Gentiles, and made their minds evil affected against the brethren.” AA 177"
"And it came to pass in Iconium, that they went both together into the synagogue of the Jews, and so spake, that a great multitude both of the Jews and also of the Greeks believed. But the unbelieving Jews stirred up the Gentiles, and made their minds evil affected against the brethren. Long time therefore abode they speaking boldly in the Lord, which gave testimony unto the word of his grace, and granted signs and wonders to be done by their hands. But the multitude of the city was divided: and part held with the Jews, and part with the apostles. And when there was an assault made both of the Gentiles, and also of the Jews with their rulers, to use them despitefully, and to stone them, They were ware of it, and fled unto Lystra and Derbe, cities of Lycaonia, and unto the region that lieth round about: And there they preached the gospel. And there sat a certain man at Lystra, impotent in his feet, being a cripple from his mother’s womb, who never had walked: The same heard Paul speak: who stedfastly beholding him, and perceiving that he had faith to be healed, Said with a loud voice, Stand upright on thy feet. And he leaped and walked. And when the people saw what Paul had done, they lifted up their voices, saying in the speech of Lycaonia, The gods are come down to us in the likeness of men. And they called Barnabas, Jupiter; and Paul, Mercurius, because he was the chief speaker. Then the priest of Jupiter, which was before their city, brought oxen and garlands unto the gates, and would have done sacrifice with the people. Which when the apostles, Barnabas and Paul, heard of, they rent their clothes, and ran in among the people, crying out, And saying, Sirs, why do ye these things? We also are men of like passions with you, and preach unto you that ye should turn from these vanities unto the living God, which made heaven, and earth, and the sea, and all things that are therein: Who in times past suffered all nations to walk in their own ways. Nevertheless he left not himself without witness, in that he did good, and gave us rain from heaven, and fruitful seasons, filling our hearts with food and gladness. And with these sayings scarce restrained they the people, that they had not done sacrifice unto them. And there came thither certain Jews from Antioch and Iconium, who persuaded the people, and, having stoned Paul, drew him out of the city, supposing he had been dead. Howbeit, as the disciples stood round about him, he rose up, and came into the city: and the next day he departed with Barnabas to Derbe."
Ellen White directly references Acts 14:1-26 in this passage.
"The apostles, however, were not turned aside from their mission, for many were accepting the gospel of Christ. In the face of opposition, envy, and prejudice they went on with their work, “speaking boldly in the Lord,” and God “gave testimony unto the word of His grace, and granted signs and wonders to be done by their hands.” These evidences of divine approval had a powerful influence on those whose minds were open to conviction, and converts to the gospel multiplied. AA 177.2"
"Long time therefore abode they speaking boldly in the Lord, which gave testimony unto the word of his grace, and granted signs and wonders to be done by their hands."
EGW directly quotes Acts 14:3.
"And they went forth, and preached every where, the Lord working with them, and confirming the word with signs following. Amen."
Both passages describe the apostles preaching and God confirming their message with signs and wonders. While not a direct quote, the thematic overlap is strong.