The aim of this incisive study is to clarify the symbolism of the so-called 'sin' (hatta't) offering, better understood as a purification offering. A major concern of the work is to explain the variety of the atonement ceremonies in Leviticus in which the 'purification offering' appears. This variety has hitherto been explained as the result of tradition-historical development (Janowski), or in terms of degrees of uncleanness (Milgrom). Dr Kiuchi presents a new way of looking at the evidence for the offering with special reference to the two incidents in Leviticus 10. The concept of atonement (kipper) includes both purification and guilt-bearing, for when the priest purifies sancta he bears the guilt associated with the uncleanness. The varieties of blood manipulation are determined by the occasion, while the varieties of disposal of the sacrificial flesh hinge on whether the agent of the atonement is also a beneficiary of it.