barsman

…carried in his hand the barsman (barsom), or bundle of sacred grass. His mouth was covered to prevent the sacred fire from being polluted by his breath. The practice of animal sacrifice, abhorred by the modern followers of Zoroaster, is attested for the Sāsānian period at least as late as…

…cognate word, Avestan barəsman (Iranian barzman), is used for a bundle of sticks—later thin metal rods—that is manipulated by the priest.