An oral history from the Irish church:
At the moment when the high pile of brushwood, crowned with flowers, was about to be lighted up by the hands of the Chief Druid, the King's eyes sparkled with rage, for eastward a weak but steady light was beheld glimmering. "Who," said he, "has dared to commit this sacrilege? " "We know not," was the answer from many voices in the assembly. "O King," said the Chief Druid, "if this fire be not extinguished at once, it will never be quenched. It will put out our sacred fires, and the man who has enkindled it will overcome thee, and he and his successors rule Erinn to the end of time." "Go, then," said Leoghairé, "quench his light, and bring him hither." "We go," was the answer; "but let all in the assembly turn their backs toward the magic blaze. Meanwhile let our own sacred fires be kindled, and all the dwellers in Erinn rejoice in its light. When we have brought this stranger into the presence, let no one rise to do him homage."
So saying, the Chief Druid set fire to the pile, and, accompanied by two other Druids and some guards, proceeded till he came to where the saint and his assistants, in their white robes, were chanting their psalms. "What mean these incantations?" tried the Druid, curiously glancing at the hooks so unlike their own wooden staves and tablets; "or why this flame on the eve of Bealteiné, contrary to the orders of the Ard Righ and the Ard Druid? Accompany us to the assembly at Tara, and account for your disobedience; but first extinguish that ill-boding light."
Of all that sat or stood in the presence of the King, no one arose to show respect to the newly-arrived but Dubhthach, an aged Druid, and the young poet, Fiech, who thus braved the King's displeasure. He, fixing his eyes sternly on the saint and his followers, sharply addressed them. "Know ye not the law of this land, that whoever on the eve of Bealteiné kindles a fire before the blaze is seen from Tara, is devoted to death?"
Patrick then commenced, by declaring the Unity of the Godhead in a Trinity of Persons, the creation and fall of man, the necessity of a Mediator, the Incarnation of the Son of God, and our redemption thereby; the necessity of true Christian belief, and the rejection of all creature worship, not excepting that of the genial lifecherishing Beal. He then alluded to his former captivity and the object of his present mission, and besought king and people not to resist the good impulses which would be vouchsafed by God's goodness to every one who did not wilfully offer opposition to them.
The hearts of the King and the greater part of the Druids remained obdurate; but such persuasive strength was vouchsafed to the words of the saint, that very many hung on his lips with veneration and enthusiasm. The Ard Righ observed this with regret; but his power was much restricted, and he did not venture to express open dissatisfaction. He ordered apartments to be assigned to Patrick and his companions, and appointed him to argue with his Druids on the morrow.
Thousands were assembled next day on the wide plain, and the stern-looking Druids filled the greater part of the space enclosed for the disputants. After some explanations and arguments were adduced by the missionary which told heavily on the priests, the Chief cried out in an arrogant tone, "if the Son of God has redeemed the human race, and if you were sent by Him, work a miracle to prove your mission." "I will not seek to disturb the order of Providence to gratify mere curiosity," modestly answered the saint. "Then will I approve the truth of druidic worship by effecting what you fear to attempt," cried the infuriated pagan; and beginning to describe lines in the air with his wand, and to chant spells, a thick veil of snow shut out the light and heat of the sun, and covering the ground several feet, an intense cold was felt, and the teeth of every one in the assembly chattered. Cries of discontent arose, and the saint addressed the Druid: "You see how the assembly suffer; banish this snow and cold, and admit the warm sun-shine." "I cannot do so till this hour on to-morrow."
"Ah! you are powerful for evil, not for good. Very different is the gift bestowed on the messenger of the Giver of all good." He made the sign of the cross, invoked the aid of the Holy Trinity, and the snow sunk in the soil, the grass again emerged green and dry, and the blue air again appeared, warmed by the bright and comforting sunbeams. All the people invoked blessings on the head of the beneficent Apostle.
"To convince you all," cried the Druid, "of our power and that of our gods, behold what I am empowered to do!" In a few seconds darkness such as seldom shrouds the earth fell on the assembly, and they groped about and murmured. Again was the thick black cloud dispersed at the prayer of the Apostle, and thousands of tongues blessed him.
The King, wishing other proofs, cried, "Each throw his book into the water, and let him in whose book the letters remain uninjured be declared the minister of truth!" "I will not consent," said the Druid; "he has a magic power over water of which I know not the extent." "Well, then," said the King, "let the ordeal be by fire." "Nay, his magic also embraces the fire." "Well," cried the King, "we are tired; let this last trial be made. Each priest enter a tent filled with dry boughs; which shall then be set on fire." "Nay," said the Saint, "let one be filled with the branches still green, and this I resign to the opponent of my sacred mission."
Young Saint Benin, who attended night and day on St. Patrick, besought his leave to enter the hut of dry boughs, and his request was granted, he bearing the Druid's mantle, and the Druid bearing his. Both huts were fired at the same moment, and in the twinkling of an eye the Druid and the green twigs full of sap were reduced to ashes by the devouring flames, nothing being spared but the cloak of the young saint, in whose hut nought was consumed but the Druid's garment. This was the last trial which the assembly would suffer, thousands, including the queen and her daughters, openly professing their belief in the God of Patrick.