This image is based on a concrete scene from the "Fenian Cycle" which belongs to Irish mithology.
Here I am leaving the text which inspired me to create this scene:
"in the time of Finegas he was called the Salmon of the Pool of Fec, which is the place where the fair river broadens out into a great still pool, with green banks softly sloping upward from the clear brown water. Seven years was Finegas watching the pool, but not until after Finn had come to be his disciple was the salmon caught.
[...]
“Hast thou eaten of the salmon?”
“Nay,” said Finn, “but it burnt me as I turned it upon the spit and I put my thumb in my mouth”
-The High Deeds of Finn and other Bardic Romances of Ancient Ireland.
T. W. Rolleston