Mishnayos Oholos Perek 13 Mishnah 5

אלו ממעטים את הטפח – a window that its measure is when it is open a handbreadth, and one of all of these that is considered here is placed in it and it reduces the airspace from a handbreadth, it interposes, that the defilement doesn’t pass to the other side.

על ידי רובע עצמות – if there is in the house a quarter [KAB] of bones that defile in a tent, and less than an olive’s bulk from the flesh of a corpse that is placed in the window, it lessens it. And specifically, less than an olive’s bulk, for if it were an olive’s bulk, it itself defiles in a tent. And specifically, through a quarter [Kab] of bones. But if there is in the house an olive’s bulk of flesh from a corpse, nothing less than this olive’s bulk can lessen it, for on the contrary, flesh combines with flesh. And that is the reason also that specifically flesh reduces through bones, but not bones through bones, for bones with bones combine.

פחות מעצם כשעורה -but a bone like [the size of] a barleycorn does not reduce/lessen the size, because it defiles through contact and through carrying.

פחות מכזית מן המת – now [the Tanna/teacher of the Mishnah] has repeated his teaching, even though he taught it in the first clause [of the Mishnah] to inform us/teach us that he lessens/reduces [the size] through all that defile in a tent, such as a quarter [LOG] of blood and a spoonful of mass of earth from a grave containing parts of a decayed human body if of a certain quantity and all of those that are taught in Chapter Two [of Tractate Ohalot].

פחות מכזית מן הנבלה וכו' – all of these that are considered from here and onward, that they reduce whether through bones or whether through flesh.

ופחות מכביצה אוכלים – that foods less than an egg’s bulk do not defile others and are not susceptible to receive ritual defilement from the Torah, therefore it reduces and interposes in the face of the defilement.

והתבואה – that took root far from the wall and its foliage straightened and closed the window, for it is attached to the ground.

וככי שיש הן ממש (the web-like marrow of reeds/substantial spiderweb in which there is substance) – spider’s web that are called the web-like marrow of reeds. But I heard that they are a species of spider’s web that is found within the reed. And sometimes it is very thin and it is web-like marrow of reeds and there is no substance to them, and sometimes it is similar to the weaving of cloth and it is like a web-like marrow of reeds that has substance to it.

ונבלת עוף טהור שלא חישב עליה – that the carcass of fowl/birds is ritually pure and doesn’t defile until one considers it/given it thought for eating, and then it defiles with the ritual impurity of foods like an egg’s bulk and does not require certification [to be susceptible to ritual uncleanness].

נבלת עוף טמא שחשב עליה ולא הכשירה – for the carrion of an impure bird/fowl requires intention/though and requires certification [to be susceptible to ritual uncleanness, that is to say, that when water comes upon it or one of the seven liquids (i.e., dew, water, wine, olive oil, blood, milk and honey – see Tractate Makhshirin, Chapter 6, Mishnah 4), but if it is lacking thought/intention or certification of [to be susceptible to ritual uncleanness], it is pure and it reduces/lessens [the handbreadth] and interposes in the face of defilement.