Mishnayos Chullin Perek 1 Mishnah 6

כשר בפרה פסול בעגלה – The Red Heifer (literally “Red Cow” – see Numbers chapter 19) and the heifer whose neck was broken are both performed outside, but what is appropriate–valid in terms of the ritual slaughter of a red heifer is invalid for the one [heifer] whose neck is to be broken. Regarding the heifer whose neck is to be broken, at its neck [when the ceremony takes place] is valid, but if ritually slaughtered is invalid. It is found that what is valid for the cow (i.e., Red Heifer) is invalid for the heifer [whose neck is to be broken] and what is valid for the heifer [whose neck is to be broken] is invalid for the cow [i.e. Red Heifer].

כשר בכהנים פסול בלוים – Priests who have blemishes are unfit [for the altar, for priestly service], but in [matters of] age, they are fit (compared to Levites; Kohanim–Priests can begin to serve as soon as they reach the age of majority- Bar Mitzvah – and their service continues for the rest of their lives; Levites, on the other hand only serve from ages thirty through fifty and must be able to sing). Levites, [on the other hand] are considered fit to serve if they have blemishes, but in [matters of] years are unfit [for service], as it is written (Numbers chapter 8, verse 25): “But at the age of fifty they shall retire from the work force [and shall serve no more].” But in Shiloh and in the temple where there was no carrying [of the ark] by [one’s] shoulder, the years do not disqualify the Levites, but only the [matter of the] voice alone. It was found, whether one is speaking about the wilderness or Shiloh, what is valid for Priests is invalid for Levites and what is valid for Levites is invalid for Priests.

טהור בכלי טמא בכל הכלים – The hollow–air [i.e. empty space] of an earthenware vessel is impure, if the defilement approached its hollow but did not touch it (the earthenware vessel), the earthenware vessel is defiled (see Mishnah Kelim, Chapter 2, Mishnah 1 for further details), as is written concerning it (Leviticus chapter 11 verse 33): “And if any of these falls into [an earthen vessel, everything inside it shall be pure and -the vessel- itself you shall break].” But if [it fell] on its back, it is ritually pure, and even if the defilement touched its back, it was not defiled through this. The hollow–air of all utensils is pure, as long as the defilement did not touch them, even if it was suspended in its air-space. But if its backs are impure, if the filament touched its backs, they have become impure. It is found [therefore], that [whatever is] pure in an earthenware vessel, becomes impure in all of the utensils [when it is touched by something impure], but that which is pure in all [other] vessels, is impure in an earthenware vessel.

טהור בכלי עץ טמא בכלי מתכות – Unfinished wooden implements, which are [defined as] utensils which are not completely formed, but their engraving has been completed and are worthy for use are impure. But flat wooden implements are pure even if they are completely formed, as [Rabbis] made an analogy between a wooden implement and a sack, as it is written (Leviticus chapter 11, verse 32): “[And anything on which one of them falls when dead shall be impure: [be it any article of wood, or a cloth, or a skin, or a sack –[any such article that can be put to use shall be dipped in water, and it shall remain impure until evening; then it shall be pure].” Just as a sack is carried full or empty, so too anything is carried full or empty. Unfinished metal utensils are pure, since in recognition of their being made, they are not considered utensils to be filled until they are completely formed. But flat [metal] vessels are impure, for they [the Rabbis] do not make the analogy of a sack being like a wooden utensil. It is found therefore, that what is [considered] pure for a wooden utensil is impure regarding metal utensils; what is pure for metal utensils is impure for wooden utensils.

החייב בשקדיים המרים – (see Mishnah Ma’aserot, Chapter 1, Mishnah 4)[Regarding] bitter almonds, the small ones require tithing, since it is customary to eat them when they are small prior to their becoming bitter, and large ones are exempt [from tithing], since they are not worthy for eating. Sweet [almonds, on the other hand], the large ones are liable [for tithing] since their fruits have been completed, but the small ones are exempt, since it is not appropriate to eat them as such. It is found [therefore], that which liable [for tithing] regarding bitter almonds is exempt regarding sweet ones, and that which is liable [for tithing] with sweet [almonds] is exempt with bitter ones.