Tosefta su Levitico 4:36

Similarly, we do not give the priestly portion [to anyone] except to a Kohen who is a chaver, and that way we do not pay the principal and a fifth (see Lev. 4:24) except to a Kohen who is a chaver. Where a [Kohen who is an] am ha'aretz eats the priestly portion, he [must] pay the principal and a fifth to a Kohen who is a chaver, and the chaver takes Demai [as a gift] to him and thereby appeases the am ha'aretz [by offsetting the penalty].

[A person] who is cutting gavels [of grain, with intention] to bundle them into sheaves later [and not right away], and also [a person who is piling up] heaps of garlic [with intention to make from the heaps] bundles of garlic, or [spread out] onions, [later and not right away, if any of these gavels of grain or heaps of garlic, or spread out onions, have been forgotten in the field, the law of] Shikcha (forgotten sheaves) does not apply to them, [and therefore they still belong to the owner, who can go back and retrieve them.] [A person] who is binding sheaves, because of [an approaching] fire or because of an irrigation canal [that broke through and is about to flood the field, if any of these sheaves have been forgotten in the field the law of] Shikcha does not apply to them, [and therefore they still belong to the owner, who can go back and retrieve them,] because he (i.e. the farmer) will check [the field for any forgotten sheaves, since he is not harvesting them, but rather moving them out of the way of the fire or flooding water.] It happened with a certain pious person that he forgot a sheaf in his field [during harvest,] and he said to his son, “Go [to the Temple in Jerusalem] and sacrifice in my name a bull for Korban Olah (burnt-offering) and a bull for Korban Shlamim (peace-offering).” He (i.e. his son) said [back] to him (i.e. the father), “Father! What have you seen in this commandment [of Shikcha that caused you] to rejoice [about it] more than all [other] commandments that are mentioned in the Torah?” He (i.e. the father) said [back] to him (i.e. the son), “All [other] commandments [that are mentioned] in the Torah have been given to us by God [to be executed] consciously (i.e. on purpose with intent). [But] this [commandment of Shikcha was given to us by God to be executed] unconsciously (i.e. accidentally due to forgetfulness), because if we would have done it willingly (i.e. left the sheaf in the field on purpose for the poor to take) in front of God, this commandment would not be counted for us [as a fulfilled commandment of Shikcha, but rather as a random act of kindness.]” He (i.e. the son) said [back] to him (i.e. the father), “It says [in the Torah], ‘When you will harvest your harvest in your field and you will forget a sheaf in the field, do not go back to take it. It shall be [left there] for the Non-Jewish resident, for the orphan, and for the widow, in order that Hashem, your God, will bless you with all the deeds of your hand.’ (Devarim 24:19) The verse has granted him (i.e. the farmer who left the sheaf in the field) a blessing. [But why did the verse need to say explicitly that the farmer will get a blessing?] Is not it a Kal Vechomer (derivation from minor to major) [which can be concluded by us logically without the need of an explicit verse]? Just like someone who did not intend to do something good, but he [ended up] doing something good [anyway], the verse considers him as if he has done something good, so for sure someone who intended to do something good, and [ended up] doing something good [that he meant to do] how much more so [should get a blessing]?” Similarly, [it says in the Torah:] “If a soul from the common people sins by accident by doing one of the negative commandments of Hashem, and becomes guilty of it. When his sin which he sinned will become known to him … (the verses go on to describe the sacrifice that the sinner should bring) … and the priest will atone for him, and he will be forgiven.” (Vayikra 4:27-31) And it is a Kal Vechomer [which can be concluded by us logically]! Just like someone who did not intend to sin, but sinned [anyway], we consider him as if he sinned. So someone who intended to sin and [then] sinned, how much more so [should be considered as if he sinned. And therefore will for sure get punished.]

Every olive [tree] that has a [distinguished] name in the field, such as the Olive Tree of Netofah had in its time, and he forgot [to collect its produce from the field], it is not considered forgotten (Peah 7:1). What case are we talking about? About a situation where he had not started with it (i.e., not begun to harvest the tree), but if he had started with it and he forgot it, behold, it is [considered] forgotten, until the time that [the owner has harvested] two seahs (Peah 7:2).

2. Rabbi Yochana ben Zakai used to say five things.