A shrift is a penance (a prescribed penalty)
imposed by a priest in a confession in order to provide absolution.
During the 17th century, criminals were sent to the scaffold
immediately after sentencing and only had time for a 'short shrift'
before being hanged.
The first known use of short shrift was in 1594. Shakespeare was the
first to write it down, in Richard III. RATCLIFF: Dispatch, my
lord; the duke would be at dinner: Make a short shrift; he longs to
see your head.
It does not appear again in print until 1814, Scott's Lord of the
Isles: Short were his shrift in that debate. If Lorn encounter'd
Bruce!
The original meaning has little relation to the modern sense of
short shrift, which usually has negative connotations. One usually
does not want to be given short shrift or little consideration in
dealing with a person or matter.
Theologians and confessors viewed the sacrament of penance as a
prescription that cured a moral illness. In early medieval times
penances were long and arduous and had to be performed before
absolution. Lengthy pilgrimages and even lifelong exile were not
uncommon. However, less demanding penances could be given in extreme
situations; short shrift was a brief penance given to a person
condemned to death so that absolution could be granted before
execution.