פירוש על פרה 10:2

שנגע במדף טמא – The upper part of a person with gonorrhea is called a מדף /Maddaf for if there were on top of a person with gonorrhea tent-covers one on top of another, all of them are impure through indirect contact for conferring ritual impurity, even the uppermost one that the person with gonorrhea did not have contact with. Just as [the case of] ten mattresses/beds one on top of the other and a person with gonorrhea lay down on the uppermost one, all of them are ritually impure according to the Torah because of lying, and even though he didn’t come in contact/touch the lowest ones, so also the upper tent-covers that are upon the person with gonorrhea, all of them are impure according to the Rabbis because of indirect contact/מדף and מeven though he did not come in contact with them. But there is a distinction between lying to indirect contact by shaking/מדף, that the person [who defiles] by lying becomes a primary source of ritual uncleanness/אב הטומאה to defile people and vessels, but the מדף/indirect contact through shaking is not other than a secondary source of impurity/ולד הטומאה to defile food and liquids but because of the stringency of the purification/sin-offering, people and vessels that came in contact in an indirect manner through shaking/מדף are impure for a purification/sin-offering (see also Tractate Eduyot, Chapter 6, Mishnah 2 and Tractate Zavim, Chapter 4, Mishnah 6).

One who was clean for the hatat waters who touched something that has madaf uncleannes, he becomes unclean. This section is a consequence of what we learned in mishnah one. Something that has madaf uncleanness (see there for an explanation of this type of uncleanness) conveys uncleanness to a person who wants to perform the red cow ritual. The mishnah states that this is true if the person touches the object, but it is also true if he moves or carries the object.

לגין של חטאת (a flagon/bottle – smaller than a pitcher and larger than a cup of purification water) – it is a vessel that only requires rinsing to be restored to Levitical cleanness, and he wants to put in it the purification water.

A flask that was designated for the hatat waters that touched something that has madaf uncleanness, it becomes unclean. If the flask which was meant to be used for the red cow ritual touches something that has madaf uncleanness, it is impure vis a vis the red cow (it is still pure for other things). In this case the flask must actually touch the other object. Putting the object with madaf on top of the flask (without touching) will not defile it.

שנגע במדף, טמא – and it requires ritual immersion.

One who was clean for the hatat waters who touched food or liquids with his hand, he becomes unclean, but if he did it with his foot he remains clean. Food and liquids defile one's hands, and once one's hands are defiled, the rest of one's body is also considered to be defiled. When it comes to the preparation of the hatat, all food and liquid defile (as we saw in yesterday's mishnah). So if one's hands touch food or liquid, he is impure vis a vis the hatat ritual. But if one's foot touches the food or liquid, the body and even the foot remain pure.

שנגע באוכלין ומשקין – and even if they are ritually pure for heave-offering [for Kohanim] and for Holy Things.

If he moved them with his hand: Rabbi Joshua says that he becomes unclean, And the sages say that he remains clean. Rabbi Joshua holds that if he moves the food, even without touching it, it is as if he touched it with his hand and he is impure (vis a vis the hatat). The other sages disagree and hold that he is impure only if he touches the food or liquid with his hand. Moving it is not sufficient to convey impurity.

בידו טמא – according to the law of impure food and liquids which defile the hands, that someone who is ritually pure for heave-offering and for Holy Things is invalid for purification/sin-offering, and further, there is an additional stringency regarding the purification/sin-offering that its body was defiled. And therefore, when it touched his hand with food and liquids it is impure.

ר' יהושע מטמא – for he decreed that shaking an object so as to move it from place to place is because of contact/touching. But the Halakha is not according to Rabbi Yehoshua.