Excalibur in Malory

   After the sword from the stone failed him in combat with Pellinore and Merlin rescued him from death, Arthur was left without a sword. Merlin escorted him to a nearby broad lake in which Arthur could see in the midst of the lake an arm clothed in white samite clutching a scabbarded sword. For a gift which she could later ask for, Lady Lile of Avelion gifted Arthur the sword. Arthur and Merlin boarded a barge and rowed out to the sword. As soon as Arthur took the sword, the arm went underneath the water. As they were returning to Carlion, Merlin asks Arthur about the value of the Sword and its scabbard and informs Arthur that the scabbard is worth ten of the sword, for while you have on the scabbard, ye shall never lose no blood even if you are sore wounded.
   During the adventure of Balin when the Lady of the Lake comes to Arthur's court to ask for the gift Arthur promised her for the sword, she explains that Excalibur means Cut-steel.