שמות, פרק כ״ט, פסוק כ״ג

The consecration of the priests involved a specific ritual using special unleavened breads placed before God. To accompany the animal sacrifice, exactly one loaf was taken from each of the three varieties of baked goods in the basket. Each selected piece represented one-tenth of the total quantity of that particular kind [רש״י, ביאור יש״ר].

Identifying the exact nature of these baked goods brings up different perspectives. Some consider the first type to be the basic unleavened bread prepared earlier in the process [אבן עזרא]. However, the primary approach among commentators suggests this refers to the standard loaves. Following this view, the second type, characterized by its oil, is identified as a specially boiled dough [רש״י, ביאור יש״ר]. It earns this title because it absorbs a much larger amount of oil during its preparation than the other items [מזרחי, שפתי חכמים]. Conversely, another perspective flips this identification. This view argues that the standard loaves are the ones defined by oil, since oil is mixed directly into their raw dough. The boiled dough, on the other hand, is initially baked without oil, making it the plain loaf [גור אריה]. The third item is simply a very thin wafer, taken from the batch of wafers.

Burning these breads directly on the altar presents a rare exception to the standard rules of sacrifices. Normally, when bread accompanies an animal offering, such as a thanksgiving sacrifice or a Nazirite offering, the baked goods are never placed on the fire. In those standard cases, one loaf of each type is given to the priest to eat alongside specific portions of the animal meat. Yet, during this unique consecration ceremony, the separated breads were entirely consumed by the altar's fire. Moses, who served the role of the priest during this event, received only the breast of the animal as his portion, with no bread included [רש״י, ביאור יש״ר, ברכת אשר על התורה].