  Due to the expansion of our Universe, the redshift of distant objects changes
with time. Although the amplitude of this redshift drift is small, it will be
measurable with a decade-long campaigns on the next generation of telescopes.
Here we present an alternative view of the redshift drift which captures the
expansion of the universe in single epoch observations of the multiple images
of gravitationally lensed sources. Considering a sufficiently massive lens,
with an associated time delay of order decades, simultaneous photons arriving
at a detector would have been emitted decades earlier in one image compared to
another, leading to an instantaneous redshift difference between the images. We
also investigate the effect of peculiar velocities on the redshift difference
in the observed images. Whilst still requiring the observational power of the
next generation of telescopes and instruments, the advantage of such a single
epoch detection over other redshift drift measurements is that it will be less
susceptible to systematic effects that result from requiring instrument
stability over decade-long campaigns.
