Chagigah 21a (כא.) — the Talmud in English

xi.

An onen,

whose dead relative died on that day, and although he did not become impure through contact with his dead, he is prohibited by Torah law from eating sacrificial food on account of his state of mourning, and even at night he is prohibited by rabbinic decree [Meiri] —

and one lacking atonement

[those who immersed and waited until sunset, but must bring offerings for their atonement, such as a male zav, a female zava, and a woman after childbirth,] and who are prohibited from eating sacrificial food until they bring their atonement offerings —

these — an onen after his state of mourning has ended, and one lacking atonement after he has brought his atonement offering —

require immersion for

eating

consecrated food.

Since until now they had been prohibited from eating it, the Sages required them to immerse for consecrated food, lest they had diverted their attention from maintaining their purity.

But they did not

require them to immerse

for

eating

teruma.

Gemara:

We learned in the Mishna: One may immerse vessels inside other vessels for teruma, but not for consecrated food:

And we raised a question concerning it:

With regard to consecrated food, what is the reason one may not

immerse one vessel inside another vessel?

Rabbi Ila said: Because its weight

[heaviness]

of the vessel

inside

constitutes an interposition.

For with regard to consecrated food, the Sages were stringent and required concern that perhaps the weight of the inner vessel presses it against the bottom of the outer vessel, preventing the water from entering between the two vessels; consequently, the immersion of the inner vessel was ineffective [and likewise that of the outer vessel, if it too had been impure].

We challenged this:

But since the latter clause

[the fifth level of stringency in our Mishna] is explained as being

because of an interposition,

it follows that the reason for the

first clause is not because of an interposition

. For if you say that the reason for both of them is an interposition, and that the Mishna teaches us that with regard to consecrated food anything resembling an interposition disqualifies, whereas with regard to teruma it does not disqualify, there would be no need for the Mishna to repeat this, and it would suffice for it to teach it once.

As it teaches in the latter clause: The measure of consecrated food is not like

the interpositions of its immersions;

the measure of teruma.

With regard to consecrated food: he loosens it, dries it, immerses it, and afterward ties it.

And with regard to teruma: he ties it and afterward immerses it.

And we answer: In fact, the reason for the

first clause and the latter clause is an interposition

in both cases.

It is necessary

for our Mishna to teach the laws of interposition in both forms, since one interposition cannot be inferred from the other.

For had it taught us

only

the first clause,

that with regard to consecrated food one may not immerse one vessel inside another,

I would have said: This is

the reason that, with regard to consecrated food, one may not

immerse one vessel inside another

because of the weight of the vessel, which exists

in this case. The inner vessel has weight that presses it against the outer vessel, and therefore there is reason to be stringent and be concerned about an interposition.

But with regard to the latter clause, where there is no

such

weight of a vessel,

but only a knot,

I would say that with regard to consecrated food the knot likewise does not constitute

the knot

an interposition. Therefore, the Mishna teaches the level of stringency that even a knot constitutes an interposition when immersing for consecrated food.

And if it had taught us

And had it taught us

only

the latter clause,

that a knot constitutes an interposition with regard to consecrated food,

I would have said: This is the reason that, with regard to consecrated food, one may not

immerse a garment containing a knot

because

the knot is tightly fastened

[the knot is tight], and it is close to constituting an interposition.