  Optical spectropolarimetry of the luminous IRAS source FSC10214$+$4724
(z$=2.286$) reveals that the strong (\twid17\%) linear polarization detected by
Lawrence \etal\/ is shared by both the narrow UV emission lines and the
underlying continuum. This observation and the brightness of the source rule
out synchrotron emission and dichroic extinction by dust as the polarizing
mechanism, leaving scattering as the only plausible cause of the polarized
emission. The narrowness of the lines requires that the scatterers be dust
grains or cool ($<1.6\times$10$^4$~K) electrons. We can recover the spectrum
that is incident on the scattering medium provided we make some reasonable
assumptions regarding the source geometry. The scattered UV spectrum has a
power law index $\alpha$~ of $-1.2 \pm 0.6$ ($F_\nu\propto\nu^\alpha$), steeper
than what would be expected from a young burst of star formation, but similar
to many AGN.
