Πότε γίνεται παύση στο Χερουβικό; / When to break the Cheroubic Hymn?
Ιστορική αναδρομή / A study in history
Professor Ioannis Fountoulis
Book: "Answers on Liturgics Issues" ("Apanteseis se Themata Leitourgikes")
(translation/summary by D. Koubaroulis)

There are three views on where the Cherubic hymn should be broken for the Great Entrance to take place.

(a) After "ton Basilea"
(b) After "ypodeksomenoi"
(c) After "merimnan"

Which is the correct one?

Well, (a) seems to be the oldest practice which is still in use in some places today. It is justified - by the old musical manuscripts which start a kratema right after "ton Basilea" - as a musical/artistic game, an 'unexpected' break to the hymn to attract the attention of the people and signify the importance of the event. The kratema was also needed to extend the length of the first part of the chant to cover the time required for "Proskomide" which used to take place exactly at that time.

(b) The most popular practice today. It seems to be a later intellectual "correction" to (a) so that the hymn is broken in a grammatically/semantically correct place, that is a comma between subsentences of the one big sentence of the hymn.

(c) The most rare nowadays. The fact that this is the point where the left chanter takes over the chant and the fact that the clergy split the hymn at this point when they recite it in the Altar may indicate that this was the ancient breaking point.

From the above it is clear that no safe conclusions can be made. In the first centuries probably nothing was chanted during the Great Entrance (exactly as in the Liturgy of the Presanctified Gifts today) Then Psalm 23 started to get chanted (6th century). When the Cherubic hymn was written and introduced, it was probably chanted as a refrain to the verses of Psalm 23. With the years, the verses were dropped and the hymn was chanted on its own one or sometimes more times. The evolution of chanting the hymn has been complicated and it is impossible to know for sure where it used to be broken in older times.