  It is argued that the results of recent precision measurements by LHCb of the
lifetimes of charmed and bottom hyperons are very well consistent with the
description within heavy quark expansion and allow to accurately determine
matrix elements of light-flavor nonsinglet four-quark operators over the
hyperons and to accurately reproduce the difference of lifemes of $\Lambda_b$
and $\Xi_b^-$. When combined with the recent LHCb results on the decay $\Xi_b^-
\to \Lambda_b \pi^-$ this leads to prediction of a lower bound on the rate of
the decays $\Xi_c \to \Lambda_c \pi$.
