Again the trumpet needs to sound. The people are awake and are returning to God. If the whole church community fails, more needs to be done. The trumpet sounds, this time as a call to confess guilt together, in a public assembly (that designation is mentioned twice). In this, your repentance (fasting) needs to be evident. Let no one be absent. There is shared guilt. For certain members of the congregation, it can be difficult to attend this service (due to age: being too young or too old), but no one may be missing, because there is collective guilt. Even those who are innocent participate (see also Daniel in Daniel 9:1–27).
15 Blow the trumpet in Zion; consecrate a fast; call a solemn assembly;