This fact proves quite conclusively that revelational impressions are not exceptions to the general rule.
c.1300, "disclosure of information to man by a divine or supernatural agency," from Old French revelacion and directly from Latin revelationem (nominative revelatio), noun of action from past participle stem of revelare "unveil, uncover, lay bare" (see reveal). General meaning "disclosure of facts" is attested from late 14c.; meaning "striking disclosure" is from 1862. As the name of the last book of the New Testament (Revelation of St. John), it is first attested late 14c. (see apocalypse); as simply Revelations, it is first recorded 1690s.