"For stricken Israel there was but one remedy—a turning away from the sins that had brought upon them the chastening hand of the Almighty, and a turning to the Lord with full purpose of heart. To them had been given the assurance, “If I shut up heaven that there be no rain, or if I command the locusts to devour the land, or if I send pestilence among My people; if My people, which are called by My name, shall humble themselves, and pray, and seek My face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land.” 2 Chronicles 7:13, 14 . It was to bring to pass this blessed result that God continued to withhold from them the dew and the rain until a decided reformation should take place. PK 128.1"
"If my people, which are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land."
EGW directly quotes 2 Chronicles 7:14 and references the preceding verse.