Bouvier's Law Dictionary, Revised 6th Ed (1856):

RULES, English law. The rules of the King's Bench and Fleet are certain
limits without the actual walls of the prisons, where the prisoner, on
proper security previously given to the marshal of the king's bench, or
warden of the fleet, may reside; those limits are considered, for all legal
and practical purposes, as merely a further extension of the prison walls.
     2. The rules or permission to reside without the prison, may be
obtained by any person not committed criminally; 2 Str. R. 845; nor for
contempt Id. 817; by satisfying the marshal or warden of the security with
which he may grant such permission.