After witnessing the fear-inspiring event at Horeb an agreement was reached between Jehovah and the people. He would raise up a prophet to speak His words to the people and they said that they would listen and do what the prophets said. This required a heart to know, eyes to see, and ears to hear, and to bring this about a whole-hearted return was required. But from the beginning, they did not listen. The words of Jehovah, spoken by His servants the prophets were the unheard words.