What are they? Who wrote them? Did they hear them from Jesus? All these questions have only speculative answers although scholars have devoted their lives and written thick books about their answers to the questions.
As the years go by I find less and less interest in those matters. I have to fall back where I started, with my experience. George Fox said, "what dost thou say?" Here's what I say:
Jesus told me that God loves me, that I should pray to the Father, love him above all, and love my neighbor as myself.
That's all. That's all that I'm really sure in my heart that Jesus said. Re the words of Jesus in the gospels: I judge them by how congruent they are with my experience of Jesus. PTL