"that they send out of the camp": Is this speaking of all men or only the Levites, the carriers of the ark? It is, therefore, written (Ibid. 3) "From male until female shall you send out" — Scripture speaks of all men. R. Yoshiyah says "that they send out of the camp" connotes both adults and minors. You say both adults and minors, but perhaps the criterion (for inclusion) should be punishment, viz.: Just as we find re sanctuary defilement that only adults are punished, viz. (Ibid. 19:20) "And a man, if he becomes unclean and does not purify himself, that soul shall be cut off" — here, too, only adults are intended.
It is, therefore, written "From male until female shall you send out," both adults and minors. R. Yochanan says: Why is it written "From male until female shall you send out"? Because it is written "They shall send out of the camp," I might think, only these (viz. (Ibid. 2). Whence do I derive (the same for) all the other types of tumah?
From "From male until female — any (type of tumah) that affects male or female — shall you send out." This tells me only of male and female. Whence do we derive the same for one whose sex is unknown or a hermaphrodite? From (the redundant) "Outside the camp shall you send them."
This tells me only of one who can be sent away (i.e., of one who can walk). Whence do I derive (the same for) one who cannot be sent away (i.e., that he must be taken by another)? From "Outside the camp shall you send them." This tells me only of men.
Whence do I derive (the same for) appurtenances (that have become tamei)? From "and they shall not make unclean their camps." R. Akiva says: "Outside of the camp shall you send them" connotes both men and appurtenances. R. Yishmael says: It is derived by induction, viz.: A man is subject to plague tumah and garments are subject to plague tumah.
Just as a man is subject to being sent away, so, appurtenances. — No, this may be so for a man, who imparts tumah (to an object) by reclining (mishkav) or sitting (moshav [upon it]), for which reason he must be sent away — as opposed to appurtenances, which do not impart tumah in that manner! — No, this is refuted by (the instance of) stones from a leprous house, which, though they do not impart tumah through mishkav or moshav, require being sent away.
Do not wonder, then, if appurtenances, though they do not impart tumah through mishkav and moshav are to be sent away. R. Yossi Haglili says "From male until female shall you send them out": Just as male and female are distinctive in being subject to becoming proto-tumah (av hatumah) require being sent away, so, all that are thus susceptible — to exclude earthenware vessels, which are not thus susceptible.