The subject of this painting is The Rider on a White Horse of Apocalypse of St. John: "And I saw, and behold, a white horse, and he that sat thereon had a bow; and there was given unto him a crown: and he came forth conquering, and to conquer."1 This theme was developed by Swedenborg in his book The White Horse.2 One may presume that Philippe Smit, a devoted reader of the philosopher and theologian, was thus incited to execute this painting.
However, no source explains the replacement of the bow by the banner, and for now only the freedom of the artist’s imagination can be posited.
1. Revelation 6:2, English Revised Version.
2. Swedenborg, Emanuel, "On the White Horse, Mentioned in Apocalypse, Chap. XIX with Particulars Respecting the Word, and Its Spiritual Sense, Extracted from the Arcana Coelestia", New York: American Swedenborg Printing and Publishing Society, 1871.