Contained within Maimonides’ Hilchot Bechorot is a famously puzzling ruling, which seems to contradict the Talmud on which it is based.

Before citing Maimonides, we must explore the relevant section of Talmud.

At the start of tractate Bava Metzia, the Talmud spends a considerable amount of time discussing the laws regarding two individuals who claim exclusive ownership of an article. In certain situations, we may say that if one of the two seized the article, we would not remove it from this individual's possession (kol dealim gavar). At this point the Talmud wants to know what the law would be in such a case—where if one of the two seized the item we would not remove it from his possession—but instead of seizing it, one of the claimants went ahead and sanctified the article for use in the Beit Hamikdash (hekdesh). Is the sanctification valid, even if the item is not in his possession?

To elucidate this, Rav Hamnuna quotes a Mishnah: The law is that a kohen is entitled to various firstborns (or a redemption payment in lieu of the first born) born to a non-kohen. There are three categories of firstborns that a kohen may have a right to.

1) A firstborn male child: Five selahim are given to the kohen as a redemption for the firstborn child. (This is known as pidyon haben.)

2) A male firstborn cow or sheep: Such an animal is considered holy from birth, one may not use its wool or use it for any work. If there is no blemish on this animal, it is sacrificed in the Beit Hamikdash and the kohen consumes its meat. If it develops an invalidating blemish, the kohen may slaughter it and eat like a regular animal.

3) A firstborn male donkey is redeemed with a lamb, the lamb is given to a kohen. This lamb does not have additional holiness.

The Mishnah discusses a case where there is uncertainty whether or not this child or animal is in fact a firstborn.

If there is uncertainty with regard to firstborns, whether a human firstborn or an animal firstborn, whether with regard to kosher cattle or non-kosher animals, i.e., the firstborn of a donkey, the burden of proof rests upon the claimant. And it is taught in that regard in a baraita: One is nevertheless prohibited from shearing and from working the kosher cattle, as their status as firstborns is uncertain and they are considered holy.1

Rav Hamnuna explains that this Mishnah implies that: 1) the burden of proof is on whoever is seeking to extract in court, as it states that “the burden of proof is upon the claimant.” Therefore, in a case where a kohen seized the uncertain firstborn, we would not remove it from his possession. 2) Even in a scenario where the kohen did not seize it, it is still considered holy and one may not work with the animal or benefit from its wool. This is due to the fact that the kohen could have seized it, denoting that he has some stake in this animal. Evidently, even when the item is not in an individual's possession, if he has some claim over it—denoted by the fact that if he would seize the animal we would not extract it from him—it can still be considered hekdesh. This resolves the Talmud’s original quandary.

Rabba, however, dismisses this proof: The truth is, says Rabba, we can interpret the Mishnah to mean that if the kohen seized the animal, we would indeed remove it from his possession. When the Mishnah states that “the burden of proof is upon the claimant” it is in fact not referring to the individual seeking to extract from the kohen who seized, but rather the burden of proof is on the kohen, and we therefore return it to the non-kohen unless the kohen can prove his ownership. The kohen is considered the claimant here. Indeed, Rabba suggests that the reason one may not work with the animal or use its wool is not due to any intrinsic right that the kohen has to this animal. Rather, it is due to the way this animal received its ‘holy’ designation.

In the case the Talmud is unsure about, when one of the two individuals actively consecrated the item, the question is whether or not the consecration is valid. Of course, in order to affect a valid consecration, the person consecrating must have some kind of right to the item. In the case of the Mishnah quoted by Rav Hamnuna, however, we are dealing with a (possible) prior consecration. The kohen was not the one who did the act of consecration. As soon as this animal was born, there is an automatic possible consecration, due to the possibility that it is a firstborn. This is why in the case of the Mishnah, even though if the kohen seizes it we return it to the original owner, certain limitations are nevertheless placed on this animal due to its inherent (possible) holiness. The kohen has no specific right to it; it is consecrated at birth. This case therefore has no bearing on the issue the Talmud seeks to resolve, where both parties have equally valid claims to the article in dispute.

Rav Chananya then proceeds to cite a proof to Rabba’s position, that if the kohen seized this animal whose status as firstborn is uncertain, the court removes it from his possession, as the kohen has no monetary rights to this animal:

Rav Chananya said to Rabba: A halakha is taught in a baraita that supports your position: The animals whose status as firstborn are uncertain enter the pen to be tithed. They are brought in together with the rest of the young animals from whom the animal tithe is separated. This is so despite the fact that the halakhot of animal tithe do not apply to a firstborn animal. And if it enters your mind to say that in the case of an animal whose status as firstborn is uncertain that is seized by a kohen, the court does not remove it from his possession, why do these animals enter the pen? Isn’t this a case of the owner exempting his property from the animal tithe with the property of a kohen? If the kohen has some right to this animal, it cannot be used as a tithe since obligation to tithe pertains solely to one’s own animals.2

The Talmud is referring to a case where a farmer is counting his flock to determine his maaser obligation. Each 10th animal is given to the kohen as a tithe. If it’s true that we do not extract the animal from the kohen, showing that he has some monetary right to this animal, this would mean that the non-kohen is satisfying his tithing requirement with an animal that the kohen has some kind of claim to. From the fact that the non-kohen can count this uncertain firstborn within his flock, it is clear that in fact the kohen has no right to this animal and therefore we would remove it from his possession if he did seize it.

The Talmud attempts to discount this proof, but subsequently concludes that this baraita is indeed a proof to the position of Rabba that the kohen has no monetary claim to the animal.3 Additionally, the Talmud establishes that the exact case referred to in the baraita is regarding a lamb which was redeemed for an uncertain firstborn donkey (this will be important soon).

With this in mind we turn to Maimonides, who seems to rule in conflict to the conclusion of the Talmud. In Hilchot Bikkurim4 he rules in accordance with the baraita that this lamb (with which the uncertain firstborn donkey was redeemed) must be tithed like any ordinary animal, meaning that it belongs solely to the non-kohen. However, he also rules that in a case where a kohen seized an uncertain firstborn animal, the court would not remove it from his possession. (Which seems to denote that the kohen does in fact have a valid stake in this animal.)5 How can these two rulings be reconciled?

The Rashba’s Resolution

The Rashba6 explains the reasoning behind Maimonides’ ruling. There are two aspects to this.

Firstly, Rabba—who disagreed with Rav Hamnuna—merely stated that it is possible to read the Mishnah cited by Rav Hamnuna differently and interpret the term “the burden of proof rests upon the claimant” as referring to the kohen. Meaning that we extract it from the kohen as the burden of proof is on him, and he had no right to seize it. (In Rav Hamnuna’s reading the burden of proof was on whoever was trying to claim in court, which in this case would be the non-kohen.) The simple reading of the Mishnah seems to support Rav Hamnuna’s view. The court judges what it sees: a non-kohen seeking to extract from the kohen, therefore the burden of proof is on the non-kohen.

Secondly, the proof cited to support Rabba’s position is potentially no proof at all. Even though the Talmud does not articulate a refutation to the proof brought by Rav Chananya to the position of Rabba, this proof is in fact discounted by the conclusion of the Talmud. Once we establish that there is no proof to the position of Rabba, we can understand why Maimonides chooses not to rule in accordance with his opinion.

How does this work? The proof of Rav Chananya was from the baraita which stated that animals of questionable status enter into the pen to be tithed. If we were to say that the kohen had a right to this animal, it would not be tithed, since it belongs partly to the kohen. It is therefore obvious that the kohen has no claim, and if he were to seize it, we would indeed extract it from his possession as Rabba stated.

However, at this stage, the Talmud had not established which category firstborn we are referring to. The Talmud subsequently investigates this, first suggesting that we are referring to uncertainty regarding firstborn cattle, however, it is quickly established that this cannot be the case as such an animal would definitely not be subject to tithing. Such an animal is considered ‘holy’ due to its doubtful status. This is because if it were in fact to be a firstborn it would be offered as a sacrifice, it would not simply be given to the kohen for his use (as explained above in category two), therefore the baraita cannot be referring to such an animal.

The Talmud therefore concludes that we are in fact referring to the third category outlined above—uncertainty pertaining to a firstborn donkey. In a regular case, the donkey is redeemed with a lamb, which is given to the kohen for regular use. This lamb has no additional holiness, and would be subject to the regular tithe. This is what the baraita is referring to: if you had a lamb redeemed from a donkey regarding which there was uncertainty pertaining to its firstborn status—i.e we were unsure if the donkey was in fact a firstborn—such an animal enters the pen with the other animals to be tithed.

Being that this is the case, says the Rashba, this disqualifies the baraita as a proof for Rabba, as there is a fundamental distinction between this case and the case Rabba was discussing.

In the case of the baraita, this lamb was used to redeem an uncertain firstborn donkey. Before this point in time, the lamb belonged exclusively to the non-kohen. This is the key difference. Since this lamb was previously owned by the non-kohen, we say that his chazakah (claim) is strong enough for us to say that we leave it in his possession. If the kohen were to seize it, we would return it. This is why it 'enters the pen to be tithed', since it belongs fully to the non-kohen as he was the proven owner of the lamb before this episode occurred.

However, Rabba and Rav Hamnuna were discussing a kohen who seized an animal that was itself an uncertain firstborn. In this case, there was no owner that ever had full rights to this animal. The moment it was born, this uncertainty existed. Therefore there is no reason for us to return it; there was no “original owner.” We would therefore seemingly say (in line with the opinion of Rav Hamnuna) that whoever seizes it keeps it, not like Rabba who suggested that we return it to the non-kohen. Since it belongs to both of them equally, there is no reason to say that we remove it from the kohen’s possession.

So it turns out that after the Talmud explores the particulars of the case cited as a proof, we can see that it is no proof to Rabba at all, which is why Maimonides rules in accordance with Rav Hamnuna and not Rabba.7

Practical Application

On various occasions,8 The Lubavitcher Rebbe drew on the principle that “the burden of proof rests upon the claimant” to illustrate a spiritual lesson.

Before one prays in the morning, it appears that this world is purely a physical entity and we therefore see ourselves as separate autonomous beings, not necessarily connected to G‑d. With this perspective, one assumes that what is permitted is certainly permitted and what is unknown is presumably permitted too. At this point in time, spirituality must prove itself "the burden of proof rests upon the claimant,” would refer to the fact that physicality is the dominant force, spiritually is the claimant that must prove its existence.

However, through prayer, our entire perspective shifts. Now we realize that G‑d is constantly recreating the entire cosmos every single moment, and that what is true and real is spirituality. Now, with this change of perspective, “the burden of proof rests upon the claimant” refers not to the spiritual but to the physical. To shake one's post prayer perspective, the mundane and physical would need to assert itself. The default has become holiness.