Quite a few people, including Peggy Noonan, are referring to Bonaventure’s Life of Francis. The famous anecdote about Francis hearing a voice coming from a cross directing him to “Go, and repair my house, which is falling into ruin” is from Bonaventure’s Life.
Bonaventure could not have known Francis personally—Francis died when Bonaventure was a small child. It’s likely he was acquainted both with Brother Leo and Thomas of Celano. How well is not known.
Bonaventure’s Life of Francis is frequently given as a primary source on Francis but I’m skeptical. It’s too much the life of a saint. It’s too much a legend. As important a work as it is, I consider Bonaventure’s Life of Francis to be a secondary source and, since my post yesterday focused on the historical Francis, I omitted it there.