Theory:

Diacope is a kind of repetition where the repeated words will have a word or few in between them.
Pronunciation Guide:
Diacope: Dia (as is Diana)-- co (as in code)-- pe (as in pin)
This kind of repetition is similar to epizeuxis. The difference is that: there is no break given to the repeated words in epizeuxis; but, on the other hand, the repeated words are separated by one or two words in the case of diacope.
 
Let us have some examples now!
 
The following is an extract from the poem "Fear No More" by William Shakespeare.
Example:
Fear no more the lightning-flash,
Nor the all-dreaded thunder-stone;
Fear not slander, censure rash;
Thou hast finished joy and moan:
All lovers young, all lovers must
Consign to thee, and come to dust.
In the poem, the phrase "all lovers" are repeated but with the word "young" in between them. So, the word young has separated the repeated words "all young". Without the words in between, the repetition would have become epizeuxis. However, due to the break, the repetition become diacope!
 
The following is an extract from Rabindranath Tagore's "Vocation".
Example:
When the gong sounds ten in the morning and
I walk to school by our lane,
Every day I meet the hawker crying,
Bangles, crystal bangles!”
The line "Bangles, crystal bangles" is an example of diacope. The word crystal has separated the repeated words bangles.
In diacope, the repeated words could be separated by more than one word. Sentences such as "I have it and I will not give it to you", "to be, or not to be", "she is a doctora sweet and compassionate doctor" are examples of diacope. In the above-given sentences, the number of words between the repeated words vary. There were \(3\) words in the first sentence, \(2\) words in the second sentence, and \(4\) in the third sentence. 
Diacope used in the poem "A Legend of the Northland":
Away, awayin the Northland,
Where the hours of the day are few,
And the nights are so long in winter
That they cannot sleep them through;
 
Where they harness the swift reindeer
To the sledges, when it snows;
And the children look like bear’s cubs
In their funny, furry clothes:
 
They tell them a curious story —
I don’t believe ’tis true;
And yet you may learn a lesson
If I tell the tale to you.
 
Once, when the good Saint Peter
Lived in the world below,
And walked about it, preaching,
Just as he did, you know,
 
He came to the door of a cottage,
In travelling round the earth,
Where a little woman was making cakes,
And baking them on the hearth;
 
And being faint with fasting,
For the day was almost done,
He asked her, from her store of cakes,
To give him a single one.
 
So she made a very little cake,
But as it baking lay,
She looked at it, and thought it seemed
Too large to give away.
 
Therefore she kneaded another,
And still a smaller one;
But it looked, when she turned it over, 
As large as the first had done.
 
Then she took a tiny scrap of dough,
And rolled and rolled it flat;
And baked it thin as a wafer —
But she couldn’t part with that.
 
For she said, “My cakes that seem too small
When I eat of them myself
Are yet too large to give away.”
So she put them on the shelf.
 
Then good Saint Peter grew angry,
For he was hungry and faint;
And surely such a woman
Was enough to provoke a saint.
 
And he said, “You are far too selfish
To dwell in a human form,
To have both food and shelter,
And fire to keep you warm.
 
Now, you shall build as the birds do,
And shall get your scanty food
By boring, and boring, and boring,
All day in the hard, dry wood.”
 
Then up she went through the chimney,
Never speaking a word,
And out of the top flew a woodpecker,
For she was changed to a bird.
 
She had a scarlet cap on her head,
And that was left the same;
But all the rest of her clothes were burned
Black as a coal in the flame.
 
And every country schoolboy
Has seen her in the wood,
Where she lives in the trees till this very day,
Boring and boring for food.
Thus, the repetition used in the lines "And rolled and rolled", "By boring, and boring, and boring", and "Boring and boring for food" are examples of diacope as there is a word in between the repeated word.
Reference:
  • National Council of Educational Research and Training (2006). Beehive. Fear No More-William Shakespeare (pp. 137). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.
  • National Council of Educational Research and Training (2006). Honeysuckle. Vocation-Rabindranath Tagore (pp. 109). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.
  • National Council of Educational Research and Training (2006). Beehive. A Legend of the Northland-Phoebe Cary (pp. 65 - 67). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.