Jehovah established this through the prophet Isaiah: “My word... will not return to me without results, but it will... have certain success in that for which I have sent it. ”
وَيَهْوَهُ يُؤَكِّدُ ذلِكَ بِفَمِ ٱلنَّبِيِّ إِشَعْيَا :‏ « كَلِمَتِي .‏ .‏ .‏