The agus "and" is pronounced nearly as "oggus." The story I have not traced, but it may have come from an Irish version of one of the apocryphal gospels.
THE STORY
Let us go to the mountain
All early on the morrow,
(Ochone! agus ochone, O!)
"Hast thou seen my bright darling,
O Peter, good apostle?"
(Ochone! agus ochone, O!)
"Aye! truly O Mother
Have I seen him lately,
(Ochone agus ochone, O!)
Caught by his foemen,
They had bound him straitly,"
(Ochone agus ochone, O!)
"Judas, as in friendship,
Shook hands, to disarm him,"
(Ochone agus ochone, O!)
Oh, Judas! vile Judas!
My love did never harm him.
(Ochone agus ochone, O!)
No child has he injured,
Not the babe in the cradle,
(Ochone agus ochone, O!)
Nor angered his mother
Since his birth in the stable.
(Ochone agus ochone, O!)
When the demons discovered
That she was his mother,
(Ochone agus ochone, O!)
They raised her on their shoulders
The one with the other;
(Ochone agus ochone, O!)
And they cast her down fiercely
On the stones all forlorn,
(Ochone agus ochone, O!)
And she lay and she fainted
With her knees cut and torn,
(Ochone agus ochone, O!)
"For myself, ye may beat me,
But, oh, touch not my mother,"
(Ochone agus ochone, O!)
"Yourself,—we shall beat you,
But we'll slaughter your mother."
(Ochone agus ochone, O!)