Detailed descriptions of the spear's special use and terrible effect are to be found in the Middle Irish texts Togail Bruidne Dá Derga and Mesca Ulad, both of which employ the so-called "watchman device" to describe the fearful appearance of the warriorDubthach Dóeltenga. In Togail Bruidne Dá Derga, it appears when the spies of Ingcél Cáech report on Conaire's large retinue of warriors in the hostel of Da Derga in Leinster. Lomnae Drúth observes: The interpreter Fer Rogain identifies the figure as Dubthach Dóeltenga and explains: In Mesca Ulad, Medb's watchmen paint a very similar picture when they describe one of the approaching warriors: Cú Roí then explains to Medb and her company that the watchmen have just seen Dubthach, who has borrowed the Lúin of Celtchar, and that a cauldron of red blood stands before him "so that it would not burn its shaft or the man who carried it were it not bathed in the cauldron of poisonous blood; and it is foretelling battle that it is." This latter quality has been taken to mean that such "sensitive spears... by their vibration, portended the imminence of battle and slaughter." A late version of the saga Cath Ruis na Ríg gives a more succinct account of the Luin, but also adds a number of details, such as the use of four mercenaries to keep the cauldron in place. Obviously, the weapon needed to be handled with extreme care. According to his death-tale, Celtchar was accidentally killed by his own spear in a way which emphasises its excessive heat. When he had used the Lúin to slay a hound which had been ravaging the country, he placed it upright with the spear-point upwards and so a drop of the hound's blood which trickled down along the spear went through him and killed him.
Circulation
In the Ulster cycle, Celtchar's Lúin is used by various warriors of Ulster and Connacht. Dubthach had use of it, and Dubhthach himself was slain by Fedlimid who wielded Lúin Celtchar according to a notice following the Togail Bruidne Dá Choca According to a poem by Cináed ua hArtacáin, the Connacht champion Mac Cécht used it to slay Cúscraid Menn, son of Conchobor mac Nessa. There is also a tract in TCD MS 1336, col. 723 which claims that the spear survived into the reign of Cormac mac Airt, and came to be known as the Crimall of Birnbuadach causing Cormac's blinding and rendering him unfit for kingship. Moreover, it alleges this was the "Famous yew of the wood", the name by which the spear of Lug mac Eithliu of the Tuatha Dé Danann was called. This tract occurs as a postscript to a later version of The Expulsion of the Déisi found in the same MS, but is known only by the brief English recap provided by Hennessy.
Spear of Lug?
and R. S. Loomis, proponents of the Irish origin of the Grail romances, argued that Celtchar's Lúin was to be identified with the spear of Lug, a weapon which is named in Middle Irish narratives as one of the four items which the Túatha Dé Danann introduced to Ireland. A connection may have been drawn implicitly by Togail Bruidne Dá Derga, which claims that the Lúin was found in the Battle of Mag Tuired, elsewhere known as the battle in which the Túatha Dé Danann led by Lug defeated the Fomoiri. Moreover, a tale of later date, the Early Modern IrishOidheadh Chloinne Tuireann describes the spear of Lug in ways which are reminiscent of Celtchair's Lúin. However, the Middle Irish references to Lug's spear do not correspond closely to the Lúin.
Texts
Cináed Ua Hartacáin, "Fianna bátar i nEmain", ed. Whitley Stokes, "On the deaths of some Irish heroes." Revue Celtique 23 : 303–48.
Togail Bruidne Dá Derga, ed. Eleanor Knott, Togail Bruidne Da Derga. Dublin, 1936; tr. Jeffrey Gantz, Early Irish Myths and Sagas. Harmondsworth: Penguin, 1986.
Mesca Ulad, ed. J. Carmichael Watson, Mesca Ulad. Mediaeval and Modern Irish Series 13. Dublin, 1941; tr. John T. Koch, in The Celtic Heroic Age, ed. John T. Koch and John Carey. 3d ed. Andover, 2000. 106-27; ed. and tr. W.R. Hennessy. Mesca Ulad: or, the Intoxication of the Ultonians. Todd Lecture Series 1. Dublin, 1889.
Aided Cheltchair mac Uthechair, ed. and tr. Kuno Meyer, The Death Tales of the Ulster Heroes. Todd Lecture Series. Dublin, 1906. 24–31. .
"The Expulsion of the Déisi". The relevant portion has remained unedited and was not reproduced in the edition by Vernam Hull, "The later version of the Expulsion of the Déssi." ZCP 27 : pp. 14–63.
Cath Ruis na Ríg, ed. and tr. Edmund Hogan, Cath Ruis na Ríg for Bóinn. Todd Lecture Series 4. Dublin, 1892.