<P> In Old French sources this then became Escalibor, Excalibor, and finally the familiar Excalibur . Geoffrey Gaimar, in his Old French L'Estoire des Engles (1134 - 1140), mentions Arthur and his sword: "this Constantine was the nephew of Arthur, who had the sword Caliburc" ("Cil Costentin, li niès Artur, Ki out l'espée Caliburc"). In Wace's Roman de Brut (c. 1150 - 1155), an Old French translation and versification of Geoffrey's Historia, the sword is called Calabrum, Callibourc, Chalabrun, and Calabrun (with alternate spellings such as Chalabrum, Calibore, Callibor, Caliborne, Calliborc, and Escaliborc, found in various manuscripts of the Brut). </P> <P> In Chrétien de Troyes' late 12th - century Old French Perceval, Arthur's knight Gawain carries the sword Escalibor and it is stated, "for at his belt hung Escalibor, the finest sword that there was, which sliced through iron as through wood" ("Qu'il avoit cainte Escalibor, la meillor espee qui fust, qu'ele trenche fer come fust"). This statement was probably picked up by the author of the Estoire Merlin, or Vulgate Merlin, where the author (who was fond of fanciful folk etymologies) asserts that Escalibor "is a Hebrew name which means in French' cuts iron, steel, and wood"' ("c'est non Ebrieu qui dist en franchois trenche fer & achier et fust"; note that the word for "steel" here, achier, also means "blade" or "sword" and comes from medieval Latin aciarium, a derivative of acies "sharp", so there is no direct connection with Latin chalybs in this etymology). It is from this fanciful etymological musing that Thomas Malory got the notion that Excalibur meant "cut steel" ("' the name of it,' said the lady,' is Excalibur, that is as moche to say, as Cut stele"'). </P> <P> In Arthurian romance, a number of explanations are given for Arthur's possession of Excalibur . In Robert de Boron's Merlin, the first tale to mention the "sword in the stone" motif, Arthur obtained the British throne by pulling a sword from an anvil sitting atop a stone that appeared in a churchyard on Christmas Eve . In this account, the act could not be performed except by "the true king," meaning the divinely appointed king or true heir of Uther Pendragon . As Malory's writes: "Whoso pulleth out this sword of this stone and anvil, is rightwise king born ." This sword is thought by many to be the famous Excalibur, and its identity is made explicit in the later Prose Merlin, part of the Lancelot - Grail cycle . The challenge of drawing a sword from a stone also appears in the Arthurian legends of Galahad, whose achievement of the task indicates that he is destined to find the Holy Grail . </P> <P> However, in what is called the Post-Vulgate Cycle, Excalibur was given to Arthur by the Lady of the Lake sometime after he began to reign . In the Vulgate Mort Artu, Arthur is at the brink of death and so orders Griflet to throw the sword into the enchanted lake; after two failed attempts (as he felt such a great sword should not be thrown away), Griflet finally complies with the wounded king's request and a hand emerges from the lake to catch it . This tale becomes attached to Bedivere instead of Griflet in Malory and the English tradition . Malory records both versions of the legend in his Le Morte d'Arthur, naming both swords as Excalibur . </P>

Why did merlin put the sword in the stone
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