late 14c., dispensacioun, "power to dispose of," also "act of dispensing or dealing out," also "a relaxation of the law in some particular case," from Old French despensacion (12c., Modern French dispensation) and directly from Latin dispensationem (nominative dispensatio) "management, charge," noun of action from past-participle stem of dispensare "disburse, administer, distribute (by weight)" (see dispense). Related: Dispensational.
Theological sense "method or scheme by which God has developed his purposes and revealed himself to man" (late 14c.) is from the use of the Latin word to translate Greek oikonomoia "office, method of administration" (see economy). Hence "particular period during which a religious system has prevailed" (1640s), with Patriarchal, Mosaic, Christian, etc. Also "a particular distribution (for good or ill) by divine providence" (1650s).