The Book of Hours is a prayer book that contains certain standardized prayers and texts (the "Hours" that give it its name) and, at the back of the book, a few ancillary prayers generally chosen by the person who commissioned the book. While the rest of the book was in Latin, these extra prayers were increasingly written in the vernacular as time went on.
It was rare for “catechetical” text such as the ten commandments or Apostle’s Creed to be included, and suggests that this book was more voluminous than the average Book of Hours.
According to Sewright, in the 15th and 16th centuries, catechetical texts such as the Ten Commandments were taught orally, accompanied by a simple melody to make it easier for the children to memorize the text. This version is one of at least four different rhyming versions of the Ten Commandments current in France during the 15th century, and was apparently the first one taught to very small children.