were pearls ...
The line is from Shakespeare's Tempest (I.2.398). Ariel's song to the shipwrecked Ferdinand, who was "sitting on a bank / Weeping again the King my father's wrack," when "this music crept by me on the waters." The song is about the supposed drowning of Ferdinand's father, Alonso. The Waste Land contains many references to The Tempest. Ferdinand is associated with Phlebas and Mr. Eugenides and, therefore, with the "drowned Phoenician sailor." (NA)