An oFonusa 大幣 which I have translated as ‘Grand Staff’ was an implement used in the major purification rituals. They were lengthy rods to which were tied streamers of cloth and paper. At the conclusion of the formal ritual, people would attempt to grab hold of them and rub them on their bodies to remove any impurities they might have, following which they would be thrown in the river to carry the accumulated pollution away from Heian-kyō. The lady’s poem implies that the man’s affections will shift to another just as quickly as the staff is carried away by the river currents.