Early in the Communion liturgy, on page 106 and 124 of BCP 2019, we come to the “penitential rite” portion.  The rubric there states:

Then follows the Summary of the Law, or The Decalogue (page 100).

The Kyrie or the Trisagion follows.  A “vanilla” use of this page of the liturgy would therefore go as follows: Collect for Purity, the Celebrant reads the Summary of the Law, the Kyrie follows, then on to the Gloria.  But with this option of the Decalogue (or Ten Commandments), what should we do?

We should begin with a little history.  This part of the original Prayer Books contained the Decalogue only.  And it wasn’t a shortened version with congregational responses; it was the full text of the Decalogue in Exodus 20 plus congregational responses.  That was the norm, every Communion.  By 1928 in the US, more options had arisen.  The Decalogue was still the default, but shortened versions were suggested, so it wouldn’t be quite so belabored.  The Summary of the Law was added as an option after, and the Kyrie was to follow the Summary of the Law if the Decalogue was omitted.  So there were three primary choices for the penitential rite in the 1928 Prayer Book:

1. Decalogue (full text or shortened)
2. Decalogue (full or short) + Summary of the Law
3. Summary of the Law + Kyrie

A rubric also noted that The Decalogue may be omitted, provided it be said at least one Sunday in each month.  There was also this optional prayer that concluded the penitential rite:

O ALMIGHTY Lord, and everlasting God, vouchsafe, we beseech thee, to direct, sanctify, and govern, both our hearts and bodies, in the ways of thy laws, and in the works of thy commandments; that, through thy most mighty protection, both here and ever, we may be preserved in body and soul; through our Lord and Savior Jesus Christ.  Amen.

Proponents of the historic prayer book tradition often complain that modern books have too many choices and options… this is one area where a classic book actually has more options than the 2019 prayer book!

With this background in mind, we should acknowledge that even though The Summary of the Law is implicitly the default penitential rite in the two 2019 Communion services, we should continue to make use of the Decalogue, conveniently provided on the pages immediately before the Communion liturgy begins.  It would be wise to adopt at least the rule of thumb of the 1928 prayer book: that we use the Decalogue at least one Sunday a month.  This Customary would add to that the weekly (and weekday) use of the Decalogue throughout the seasons of Advent and Lent, and on other appropriate times such as feasts of St. John the Baptist (a very Law-heavy preacher), or other penitential occasions.

One other observation that should be made is the text of the congregational responses in the Decalogue.  As I observed in January of last year, “The Decalogue has undergone some significant rewording.  Instead of asking God to “give us grace to keep this law” we ask for him to “incline our hearts to keep this law”, which is (again) more faithful to the old Prayer Books, and is more theologically specific.  We don’t just need “grace” to do better, but our hearts need reorientation.”  If you’re accustomed to the language of the 1979 prayer book, make sure you take note of this improvement, and perhaps point it out to your congregation (which I believe I did by the beginning of Lent that year).