The task of the chevra kadisha is considered a laudable one, as tending to the dead is a favor that the recipient cannot return, making it devoid of ulterior motives. Its work is therefore referred to as a chesed shel emet (a good deed of truth), paraphrased from Genesis 47:29 (where Jacob asks his son Joseph, "do me a 'true' favor" and Joseph promises his father to bury him in the Land of Israel).
At the heart of the society's function is the ritual of tahara, or purification. The body is first thoroughly cleansed of dirt, body fluids and solids, and anything else that may be on the skin, and then it is ritually purified by immersion in, or a continuous flow of, water from the head over the entire body. Tahara may refer to either the entire process, or to the ritual purification.