The garments of an am haaretz have midras [-contamination] for perushim. Garments of perushim have midras[-contamination] for those who eat terumah. Garments of those who eat terumah have midras[-contamination] for [those who eat] kodesh. Garments of [those who eat] kodesh have midras[-contamination] for [those who handle] purification water.  Yosef ben Yoezer was the most devout of the Kohanim; yet his napkin was [deemed to have] midras[-contamination] for [those who eat] kodesh.  Yochanan ben Gudgada used to eat according to the purity [regulations] of kodesh all his life; yet his napkin was [deemed to have] midras[-contamination] for [those who handle] purification water.