[1] Same glossing -- apart from "in an oracle" -- in other lexica. The Thucydides passage is 5.16.2 (web address 1), in respect of the oracles allegedly given in 427 BCE to Spartan delegates by Delphi at the behest of the disgraced Spartan king Pleistoanax, anxious to return from exile. The oracles declare that unless the Spartans do recall him they will have "to plow with a silver plowshare", i.e. (presumably) have difficulty in harvesting crops.