Note: after long puzzlement as to the structure of this passage I have to agree with Hajimi Murai http://www.bible.literarystructure.info/bible/23_Isaiah_pericope_e.html
Note: after long puzzlement as to the structure of this passage I have to agree with Hajimi Murai http://www.bible.literarystructure.info/bible/23_Isaiah_pericope_e.html
On further reflection – the repetition of “Have ye not known, have ye not heard” in verses 21 and 28 is not recognised in this pattern. Instead I am thinking
A vv12-17
B vv18-20
C vv21-24
B’vv25-26
C’ vv27-31
C’