Our Gemara on Amud Beis references a verse, (Vayikra 7:7), “ כַּֽחַטָּאת֙ כָּֽאָשָׁ֔ם The guilt offering is like the sin offering”, and discusses features, differences and similarities of the sin offering in comparison to the guilt offering.

Roughly, a sin offering (chattas) is brought for sins committed without awareness of the prohibition, that would have incurred kares if done intentionally (Rambam laws of unintended sins 1:1). The guilt offering (Asham) is brought for specific sins done intentionally, such as denying owing a security entrusted to you, or when in doubt if a sin was committed that would ordinarily incur a chattas if he was sure he committed it (ibid chapters 8-9.) This latter sacrifice is known as an Asham Taluy.

The Toras HaOlah (a commentary on the various sacrifices by the Rama) notes differences between the Asham and Chattas that correspondingly relate to the sins they atone for. In particular, the Asham Taluy has a contradictory quality. On the one hand it is for a lighter offense, since he is unsure if he even committed the sin in the first place, and secondly, the sin was unintentional. Because of this, psychologically speaking, it is harder to atone since there is less feeling of regret when one can rationalize that perhaps he didn’t sin. 

There are really only two differences between the Asham and the Chattas. (1) the minimum cost of the sacrifice; and (2) the manner in which the blood is sprinkled.

The minimum cost for an Asham (two selas) is higher than the chattas, and in addition to the manner in which the blood is sprinkled, blood in the vessel used for sprinkling of the Chattas has an unusual quality. Any blood from that vessel which lands on clothes must be rinsed out of the cloth within the courtyard of the Temple. Even though the blood of an Asham is essentially identical, there is no such requirement.

Toras HaOlah relates these differences to the degree of natural regret and resulting penitence in each sacrifice. The significantly higher cost of the Asham is to help alert the person to the severity of his deed, which he otherwise might rationalize. In addition, the holiness of the Chattas blood, in that it must be rinsed off of clothes within the courtyard, indicates the intrinsically higher quality of the Chattas. The blood represents the core of the penitence. Since the penitential attitude of the Asham is weaker, so too is the holiness of its blood.

In many situations, it is harder to apologize for sins that do not seem so bad in our eyes. Many of the interpersonal relational sins such as ona’as Devarim and l’shon Hora are barely acknowledged, making the teshuva and repair process more difficult. It is much harder to repent when there is less regret, but we must try.