FINN
The thumb-sucking figure on this Celtic cross is probably Finn. Whenever he required to draw upon his magical wisdom, he had only to put his finger on his "tooth of Knowledge"
Finn and the Salmon of Knowledge The 'eo fis', the Salmon of Knowledge, acquired it's supernatural wisdom through eating the nuts of nine hazel trees which fell into the Well of Seghais, the spring of the Otherworld in which it lived, and made bubbles of mystic inspiration. The well is taken to be the source of the two great rivers of Ireland, The Boyne and the Shannon. Linn Feic, a pool on the Boyne, is represented as one of the homes of the salmon. When Finn was a lad (and his name was not Finn but Demhne), he went to seek instruction from one Finn the poet, who has been described as an emanation of the timeless wisdom of the river Boyne. Finn the poet had been waiting 7 years for the salmon of Linn Feic, because it had been prophesied thet eating the salmon would bring him boundless knowledge. The salmon was caught and entrusted to Demhne to cook; but the poet told him not to eat any of it. When the lad brought him the cooked salmon, he told the poet that he had not eaten any of it but described how he had burned his thumb on the salmon and then put his thumb in his mouth. The poet said thet the boy's name from then on would be Finn, and that he was the one to whom it had been given to eat the salmon. So the lad then ate the flesh of the fish. He learned the three qualifications of a poet - that is, "knowledge that enlightens", "chewing the pith" and "incantation from tips (possibly the fingertips). Whenever, in the future, the hero put his thumb in his mouth and sang " Chewing of the pith" (perhaps raw or taboo flesh)), whatever he did not know would be revealed to him.
