https://www.metmuseum.org/art/collection/search/343138 He was a Protestant, and St. Francis is only one of three (?) non-Biblical Saints whom Rembrandt painted. He included both Crucifix and Bible in the painting, to appeal to both Catholics and Protestants, and maybe also (it's presumed by some) in the (his) hopes of reunification. Source: https://www.amazon.com/Francis-Book-Years-Saint-Assisi/dp/0020032005
