Is is thought in ancient times history and learning was memorized and passed down generationally. It was Moses who is credited that it should be written down, writing having been eventually more developed.
I am coming stronger into the understanding that to speak is extra important. It is reported that God spoke the world into existence, everything that was made was made by the Word, as it is written by St John in the first chapter.
It is good in my experience to repeat a verse over and over as if in a prayer mode, in order to build the faith to advance change. Even a verse that is not particularly seen as faith building, but rather fact revealing, is worthy of repetitious emphasis. For instance, in John 1:17 as I mention in Manna.