c.1320, from O.Fr.
dispenser "give out," from L.
dispensare "disburse, administer, distribute (by weight)," freq. of
dispendere "pay out," from
dis- "out" +
pendere "to pay, weigh" (see
pendant). In M.L.,
dispendere was used in the ecclesiastical sense of "grant license to do what is forbidden or omit what is required" (a power of popes, bishops, etc.), and thus acquired a sense of "grant remission from punishment or exemption from law," which led to the Mod.Eng. meaning. Older sense is preserved in
dispensary (1699) "place for weighing out medicines," Theological sense is from being used to translate Gk.
oikonomoia "office, method of administration."
Dispensation is from c.1374.
[di-spens] 
verb, -pensed, -pens⋅ing, noun 