Everyday cooking methods, such as baking and frying, are elevated to a state of holiness when brought as offerings on the Temple altar [ביאור יש״ר]. One such offering involves the process of deep frying [ביאור שטיינזלץ]. This is prepared in a specific deep pot, in contrast to offerings made on a flat pan [רש״י, שד״ל, ביאור יש״ר]. To contain the hot oil, this deep vessel was designed with a raised rim [רלב״ג], and some note it also had a lid [מלבי״ם]. The preparation takes place entirely inside this deep space, distinguishing it from foods simply cooked on an open, flat surface [שד״ל, מלבי״ם].
Because of the vessel's depth, the oil pools securely inside and is protected from burning in the fire. As a result, the dough fully absorbs the oil, leaving the final offering soft, flexible, and so tender that it appears to quiver when touched [רש״י, גור אריה, חומש קה״ת]. This quivering movement, along with the bubbling of the hot oil, is the primary reason for the vessel's unique name [רד צ הופמן]. Alternatively, the name might originate from the sharp sizzling sound the food makes as it fries [אבן עזרא], though the explanation focusing on the dough's soft movement is generally preferred over the focus on sound [אבי עזר].
The rules governing this deep-fried offering are closely linked to those of the flat pan offering, dictating a precise method for how the oil and dough are combined [מלבי״ם]. The preparation must begin by pouring oil into the empty vessel before any flour is even added [מלבי״ם, תורה תמימה, אדרת אליהו]. Following this initial step, the fine flour itself is mixed with oil [תורה תמימה, מלבי״ם]. The primary approach among commentators is that the entire process requires three distinct applications of oil: the initial pour into the empty pot, the mixing of the flour and oil, and a final pour over the baked loaves after they have been broken into small pieces [תורה תמימה, רד צ הופמן, חומש קה״ת]. Once the preparation is complete, the priest presents the offering at the southwestern corner of the altar [רלב״ג, ביאור יש״ר, רד צ הופמן].