Bechoros Daf 56 בכורות דַף 56

The Mishnah on the previous Daf stated: [הלקוח] או שניתן לו במתנה פטור ממעשר בהמה – [an animal] which is purchased or given to him as a gift is exempt from מעשר בהמה. This is derived from the passuk: בכור בניך תתן לי כן תעשה לשורך לצאנך – your firstborn sons you shall give to Me; so shall you do to your cattle and your flocks. This היקש between a human bechor and animals teaches: מה בניך אין בלקוח ובמתנה – just as your sons are not obtained through purchase or as a gift (but are born in the family), so too the “flocks and cattle” discussed in the passuk are not obtained through purchase or as a gift. Therefore, any acquired animal is exempt from מעשר בהמה. Although the passuk is discussing bechor of animals, not מעשר בהמה, since it says "כן תעשה" – so shall you do, we say: אם אינו ענין לבכור – if [this phrase] has no application for a bechor, which is not sanctified through a person’s action, דברחם קדוש – because it is automatically sanctified through [leaving] the womb, תנהו ענין למעשר בהמה – give it an application for מעשר בהמה, to exclude acquired animals.

The next Mishnah states: האחין (ו)השותפין – regarding brothers who are partners (in their father’s estate), the rule is: שחייבין בקלבון פטורין ממעשר בהמה – those who are obligated to pay the kolbon (which is Rabbinically required to add when giving a מחצית השקל) are exempt from מעשר בהמה, and those who are obligated in מעשר בהמה are exempt from paying the קלבון. The Mishnah illustrates: קנו מתפיסת הבית – if they obtained the animals from the [undivided] estate, it is not considered a partnership, but a single ownership; therefore, they would be obligated in מעשר בהמה (from which partners are exempt). When two heirs jointly give one shekel from the estate for their two obligations of מחצית השקל, they are exempt from giving the קלבון, as if the father had given a shekel for his two sons. If, however, they divided the estate and re-entered into partnership, they are obligated in two kolbons like any partners, and their animals are exempt from מעשר בהמה. Because the קלבון pertains to money and מעשר בהמה pertains to animals, the laws can be split: if they divided the money but not the animals, they are obligated in both the קלבון and מעשר בהמה; if they divided the animals but not the money, they are exempt from both.

Rav Anan said that the Mishnah’s law, that יורשים who divided an estate and re-entered into partnership are exempt from מעשר בהמה, only applies שחלקו גדיים כנגד תיישים ותיישים כנגד גדיים – when they divided kids against rams and rams against kids (i.e., one heir took all the kids and one took all the rams), whereby each heir exchanged his share for his brother’s, and the estate is dissolved. However, if they divided גדיים כנגד גדיים ותיישים כנגד תיישים – kids against kids and rams against rams, we say: זה חלקו המגיעו משעה ראשונה לכך – this is his portion which was supposed to be his from the beginning, i.e., it is retroactively considered to have always been his share, based on ברירה – retroactive determination. Because the estate was not dissolved through exchange, it becomes reestablished as an undivided estate when they recombine their assets (and the animals will be subject to מעשר). Rav Nachman disagrees, because he does not hold of ברירה, and even if they divide kids against kids, their rejoining is considered a new partnership. In a similar machlokes, Rebbe Elazar says the exemption from מעשר only applies if they divided nine [large] animals against ten [small] animals, but not where they divided the animals evenly by number. Rebbe Yochanan disagrees.