The answer comes from whatever object the diviner happens to see or hear.
en.wikipedia.org The other specialists were: abjurers, conjurers, diviners, enchanters, invokers, necromancers, and transmuters, each representing a school of magical study.
en.wikipedia.org She underwent a formal apprenticeship in calendar divination with a local adept, and was initiated as a diviner in 1976.
en.wikipedia.org The "haruspices", diviners of omens from sacrificed animals, were unable to read the sacrificed animals and failed to do so after repeated trials.
en.wikipedia.org The skeptics naturally scoffed, especially when diviners paced the riverside meadows, hazel twigs, willow branches and silver chains limp in their hands.
en.wikipedia.org