Objects that are “Sheafed” in Heraldry, are “bundled together”. This is common with weapons (when used in multiples on Shields). A common “Sheaf” used was The Spear. Normally, no more than 3 were used to convey the military “idea” of the image. Arrows (and sometimes Swords were “sheafed”). This imagery was very popular with Fighting Orders and Knights of the early to mid-Middle Ages.