The third movement in the Divine Office begins the day. Prime is the “first” hour of the day, not to be confused with those first two movements that are in the middle of the night. The problem with the Offices is that they are originally based on approximate times in the cycle of the sun and moon. Prime is sunrise, hence the first hour.
I could go on about the origins of the office and how the Benedictines set the standard for their use in the Christian tradition, but more important to this work is the idea of opening the day. There is a clear programmatic sunrise in the music and artwork and I think the music and art present that idea well enough.
This is the first work written separate from the first two and is highly programmatic in that sense. To repeat an earlier compositional thought, it was the first of the latest compositional ideas to be portrayed. By that I mean, it was written closer to 2009 than the other earlier works. The influence of the Saint-Saens B major prelude is, well, all too transparent.