Luther’s Small Catechism consists of the Six Chief Parts of Christian Doctrine (Section 1): the Ten Commandments, the Apostles’ Creed, the Lord’s Prayer, the Sacrament of Holy Baptism, Confession, and the Sacrament of the Altar. It also includes daily prayers (Section 2), a table of duties for Christians (Section 3), and a guide for Christians to use as they prepare to receive Holy Communion (Section 4).
This is sometimes referred to as the Enchiridion. When we confess “the doctrine of the Evangelical Lutheran Church, drawn from the Scriptures, as you have learned to know if from the Small Catechism to be faithful and true” (Rite of Confirmation, LSB Agenda, p. 29), it is only to this that we are subscribing.
An explanation section has regularly accompanied editions of Luther’s Small Catechism since the early days of Lutheranism. Luther was not the author of this explanation, instead, others wrote it while commenting on Luther’s catechism. Ultimately, the root of most current forms of the “Explanation” can be traced back to the work of Johann Konrad Dietrich in his Institutiones catecheticae, published in the 17th century. That foundational work has been updated over the generations to meet the needs of Christian educators who use the “Explanation” as the basis for catechetical training. Due to the number of contributors and to the constant editing of the text over the centuries, the work cannot be attributed to one or even a few contributors. However, on page 45 of the current edition offered by Concordia Publishing House, you will find,
This explanation has been based upon and largely includes the work of Johann Konrad Dietrich (1575–1639), Carl Ferdinand Wilhelm Walther (1811–1887), Heinrich Christian Schwann (1819–1905), and the committee that prepared the synodical catechism of 1943.
Concordia Publishing House has updated the catechism in cooperation with the LCMS since at least 1943.