"The occasion was one of the greatest profit to the multitudes assembled. The desecrated streets of the city were cleared of the idolatrous shrines placed there during the reign of Ahaz. On the appointed day the Passover was observed, and the week was spent by the people in offering peace offerings and in learning what God would have them do. Daily the Levites “taught the good knowledge of the Lord;” and those who had prepared their hearts to seek God, found pardon. A great gladness took possession of the worshiping multitude; “the Levites and the priests praised the Lord day by day, singing with loud instruments;” all were united in their desire to praise Him who had proved so gracious and merciful. Verses 21, 22 . PK 337.2"
"And the children of Israel that were present at Jerusalem kept the feast of unleavened bread seven days with great gladness: and the Levites and the priests praised the Lord day by day, singing with loud instruments unto the Lord."
EGW directly quotes and references 2 Chronicles 30:21.
"The seven days usually allotted to the Passover feast passed all too quickly, and the worshipers determined to spend another seven days in learning more fully the way of the Lord. The teaching priests continued their work of instruction from the book of the law; daily the people assembled at the temple to offer their tribute of praise and thanksgiving; and as the great meeting drew to a close, it was evident that God had wrought marvelously in the conversion of backsliding Judah and in stemming the tide of idolatry which threatened to sweep all before it. The solemn warnings of the prophets had not been uttered in vain. “There was great joy in Jerusalem: for since the time of Solomon the son of David king of Israel there was not the like in Jerusalem.” Verse 26 . PK 337.3"
"Also day by day, from the first day unto the last day, he read in the book of the law of God. And they kept the feast seven days; and on the eighth day was a solemn assembly, according unto the manner."
Both passages describe a period of extended religious observance and instruction in the law. The EGW passage highlights the impact of this period on the people and the stemming of idolatry, while the KJV passage focuses on the daily reading of the law and the observance of the feast.