[BurritoAlPastor]

Note that, at least in Thomas Malory’s telling, the arm holding Excalibur out of the lake is not the Lady Of The Lake, who is nearby on the lake. The arm holding Excalibur is neither named nor explained.

[PittleyDunkin]

Is Thomas Malory of some kind of significance?

Edit: he was apparently one of the primary fanfiction authors of the english tradition