  We report the detection of repeat bursts from the source of FRB 171019, one
of the brightest fast radio bursts (FRBs) detected in the Australian Square
Kilometre Array Pathfinder (ASKAP) fly's eye survey. Two bursts from the source
were detected with the Green Bank Telescope in observations centered at 820
MHz. The repetitions are a factor of $\sim 590$ fainter than the
ASKAP-discovered burst. All three bursts from this source show no evidence of
scattering and have consistent pulse widths. The pulse spectra show modulation
that could be evidence for either steep spectra or patchy emission. The two
repetitions were the only ones found in an observing campaign for this FRB
totaling 1000 hr, which also included ASKAP and the 64-m Parkes radio
telescope, over a range of frequencies (720$-$2000 MHz) at epochs spanning two
years. The inferred scaling of repetition rate with fluence of this source
agrees with the other repeating source, FRB 121102. The detection of faint
pulses from FRB 171019 shows that at least some FRBs selected from bright
samples will repeat if follow-up observations are conducted with more sensitive
telescopes.
