...Then came the third siege of the city which carried his name. In 860, while the Slavs were battering Constantinople, Constantine, on the Olympus of Asia Minor, was laying a trap for them. In the silence of his monk’s cell, he created the first letters of their alphabet. First, he invented rounded letters, but the Slavic language was so savage, so wild that the ink could not contain it as such – so he constructed another alphabet with bars, thus caging this strong-willed language like a bird. Later, when it was tamed and taught Greek (for languages do learn other languages), the Slavic tongue could be confined within the original, glagolithic letters…
Daubmannus relates this story on the creation of the Slavic alphabet. The barbarian tongue would not let itself be tamed. During a brief, three-week autumn, the brothers were sitting in their cell, trying in vain to trace out the letters that would later be called “Cyrillic.” The task was a difficult one. From their cell, one had an excellent view of mid-October, and the silence was the length of an hour’s walk by the breadth of two hours’.
Methodius directed his brother’s attention to four vessels sitting on the window sill just outside their cell, on the other side of the bars.
”If your door were locked, how would you bring one of those vessels over here?” he asked.
Constantine shattered one of them, then brought it bit by bit through the bars and glued it all together again with a mixture of saliva and the packed earth underfoot.
Thus they proceeded with the Slavic tongue: They broke it into pieces, put it into their mouth by passing it through the bars of the Cyrillic letters, then reconnected the fragments with their saliva and the Greek earth beneath their feet...
CYRIL, entry from the Red Book – Dictionary of the Khazars