In this Tennyson work, Sir Bedivere is told to "take Excalibur, and fling him far into the middle mere"
In the end, before Arthur died, he 
told one of his knights, Bedivere or Girflet, to throw the sword back into the water
... [DOC] [TLE] 336 Excerpt from The Passing of Arthur, from Idylls of the King by ... [PAR] 336 Excerpt from The Passing of Arthur, from Idylls of the King by Tennyson ... 
and have worn it, like a king; And, wheresoever I am sung or told In aftertime, this 
... not: take Excalibur, And fling him far into the middle mere: Watch what thou 
seest, ... Then quickly rose Sir Bedivere, and ran, And, leaping down the ridges 
lightly,... [DOC] [TLE] Full text of "Guinevere & Arthur; adapted from Tennyson's 'Idylls of ... [PAR] But when Sir Lancelot told This matter to the Queen, at first she laughed Lightly, 
... and power Will work as a charm upon them, and the nuns Will spare to ask it.