Twelfth Day Of The Month.
From BiblePortal Wikipedia
Twelfth Day Of The Month. [1]
In the evening service of the Church of England for the twelfth day of any month, the hymn after the second lesson, beginning "God be merciful unto us," etc., is omitted, because it comes in the regular psalm for the day, and would thus occasion an unnecessary and useless repetition. Stanton, Dict. of the Church, s.v.
