本文討論古埃及和西亞宗教中的潔淨儀式。首先說明水與日常生活之關係以及水的象徵意義，然後討論宗教活動中的潔淨儀式，最後提出對於潔淨儀式的解讀。作者認為，潔淨儀式雖在物質面為一種身體及環境之清潔，在經過儀式化及神聖化的過程之後，也成就了精神上純淨的象徵。從宗教的角度看，潔淨與污染是一組相對的概念，討論潔淨儀式的目的，也就是在看一宗教傳統中所謂的潔淨和污染概念是如何成立，其意義為何，又如何達到潔淨狀態。從社會的角度看，潔淨儀式為一種建立身份的辦法，因為理想的或者經常的潔淨的狀態是在經濟和社會地位到達相當程度時才能具有的條件。經過潔淨儀式之後的人就具有了一種新身份，有了新的活動領域，這也正是宗教權威之所以能夠建立的基礎之一。

This article discusses the purification ritual in ancient Egypt and Mesopotamia. The author first discusses the relationship between water and daily life, and the symbolic meaning of water. The main part of the article is devoted to the discussion of purification rituals in religious ceremonies. The author maintains that although on the material side purification ritual is only the cleansing of body and environment, it becomes symbolic of spiritual purity after ritualization and sanctification. Religiously, purity and pollution are a set of opposite concepts, and the goal of the discussion of purification ritual is to see how the ideas of purity and pollution were established, what are their meanings, and how to achieve the state of purity. Sociologically, the purification ritual could also be seen as a way to establish a special social and religious status, for it is only with the possession of certain special conditions, whether economic or religious, that the state of purification could be reached. Those who have gone through the purification ritual gained a new status, and are given a new domain to perform the power accorded by the new status. This is one of the foundations of religious authority.