The Suspensive Asham-offering
Requires Beit HaMikdash
VaYikra 5:17-18 If a person sins and did [transgress] one of the Mitzvot of Hashem that should not be done, [however], he is uncertain [that he sinned], and he [nevertheless] incurs guilt and will bear [the burden of] his iniquity. He shall bring an unblemished ram, from the sheep, based on the valuation as a Asham [Guilt]-offering, to the Kohen. The Kohen will atone for him, for the error which he did unintentionally, and he did not know, and he will be pardoned.
We are commanded to offer a certain sacrifice in case of doubt about one of these major sins for which the penalty is extinction if committed willfully, and a fixed Chataat-offering if committed unintentionally. This sacrifice is called a Suspensive Asham-offering.
An example of a case of doubt which calls for a Suspensive Asham-offering - Suppose a person has before him two pieces of fat, one being fat of the kidneys [which is forbidden food according to Torah], and the other fat of the heart [permitted food according to Torah]. He eats one of the two, and the other is eaten by another person or lost. A doubt then arises in his mind whether the piece he has eaten was the permitted or the forbidden one. In such a case he must offer a sacrifice because of the doubt that has arisen, so as to get atonement, and this is called a Suspensive Asham-offering. If it is subsequently established that the piece he ate was the fat of the kidneys, it s confirmed that he as sinned unintentionally, and must offer a fixed Chataat-offering.
A wider application of this Mitzvah:
"They told of Bab b. Buta that he offered of his own free will a Suspensive Asham-offering every day save only the day after Yom Kippur. He said, 'By this Temple! Has they allowed me, I would have offered one even then, but they said to me, 'Wait until you have come to a state of doubt.'" (Ker. 25a)