Merlin! Merlin! Where are you going
So early in the day, with your black dog?
Oi! Oi! Oi! Oi! Oi! Oi! Oi! Oi! Oi! Oi! Oi! Oi! Oi! Oi!

I have come here to search the way,
To find the red egg;
The red egg of the marine serpent,
By the sea-side in the hollow of the stone.
I am going to seek in the valley
The green water-cress and the golden grass,
And the top branch of the oak,
In the wood by the side of the fountain.
Merlin! Merlin! Retrace your steps;
Leave the branch on the oak,
And the green water-cress in the valley,
As well as the golden grass;
And leave the red egg of the marine serpent,
In the foam by the hollow of the stone.
Merlin! Merlin! Retrace your steps,
There is no diviner but God.

This is an old Cornish poem (though thought to originate in Brittany) about Myrddin, not by Myrddin himself. It gives the typical perspective of Myrddin as a druid priest, but puts a Christian spin on it, condemning him for attempting to divine the works of God. Gotten from Lyra Celtia, an old book at the West Chester University Library.

 

Lyra Celtia, ed. E. A. Sharp, J. Matthay. Edinburgh: John Grant. 2nd ed: 1924. 1st: 1896.