Comentário sobre Pirkei Avot 5:15

AMONG THOSE WHO SIT BEFORE THE SAGES. Rav writes that our mishna is discusssing good reasoning.²³⁰As opposed to mishna 12, which is dicussing the ability to remember. This is why our mishna says “who sit before the Sages.”

There are four temperaments, etc.: the sponge: [This is] a metaphor for a student who does not distinguish between a correct argument [and one that is not], similar to a sponge that collects and absorbs water - whether it is dirty or whether it is clear.

He compared the man with a good memory who remembers all that he hears and does not separate between the true and the false to a sponge - and that is a sea [sponge] that absorbs everything. And he also compared one who understands immediately but does not remember anything at all - not the true and not what is not true - to a funnel. And he compared one who rembers the bad things and the opinion that is not true and forgets the true things upon which action [needs to be based] to a strainer that only retains the sediment and lets out what is pure. And he compared the man whose way is the opposite [of this] to a sieve that lets out the dirt and dust through its holes and the fine flour remains. And from them, only this fine flour sieve is good, in that it lets out the [inferior flour] that has no purpose and holds what is coarser - and that is the fine flour.

the sponge: Sea wool - Rambam.

Among those who sit before the sages: Earlier with the "four temperaments among students," it was speaking about the topic of memory and forgetting. And now it is speaking about the topic of proper analysis and separating a thing that is right from that which is not right.

There are four types among those who sit before the sages: a sponge, a funnel, a strainer and a sieve.
A sponge, soaks up everything;
A funnel, takes in at one end and lets out at the other;
A strainer, which lets out the wine and retains the lees;
A sieve, which lets out the coarse meal and retains the choice flour.
Above in mishnah twelve we learned about four types of disciples. This mishnah is similar but instead of just describing the different types of students, it uses metaphors to compare them to different instruments in the kitchen. Furthermore, whereas that mishnah was considered with comprehension and retention, our mishnah is also concerned with the proper selection of what is worthy of retaining. The discussions in the mishnaic and talmudic study halls were probably very long, and no one could remember everything that was said. It would have been extremely important for the listeners to decide which statements were important and worthy of preservation and which were not.
A sponge, soaks up everything; The sponge soaks up all liquids, whether or not they are good or yucky. So too there are some students who remember everything that was said, whether or not it was reasonable and worthy of being remembered.
A funnel, takes in at one end and lets out at the other: The student who is like a funnel is able to take in all that is said, but he easily forgets it, like a funnel which lets everything out the other end.
A strainer, which lets out the wine and retains the lees: This is the most unfortunate type of student, who does not retain any of the well-reasoned valuable statements out, and only retains that which is not worthy of retention. It isn’t that he simply forgets the important things which were said, because he does remember some of what he has heard. Rather he cannot discern what was worthy of remembering in the first place.
A sieve, which lets out the coarse meal and retains the choice flour: After all of the bran is removed from the flour, the flour is passed through a sieve. What remains in the sieve are the larger, useful pieces of fine flour and the stuff that falls out is not useful [this is evidently not like the sieve we use today]. So too there are students who retain only that information which is important and remove the extraneous things that they have heard. This is obviously the best kind of student.

A SPONGE. Rambam: sea sponge.

the funnel: As it accepts all of the things, but loses them immediately.

the sponge: It absorbs the water, whether it is muddy or clear. So [too], there is one whose heart is broad and he receives everything that he hears [but] does not have the ability to separate the truth from the falsehood.

A SIEVE. Rav: after the bran is extracted… this is what they did with the flour offerings. As the mishna explicitly says in Menachot 6:6.

the strainer: [This is like] a student that retains in his mind the argument that is incorrect and loses the correct one. And about this King Shlomo, peace be upon him, stated (Proverbs 12:8). "A man is praised according to his intelligence, but a twisted heart is disgraced" - that it is not fitting to disgrace [one who knows less, but it is fitting to disgrace] one whose heart is twisted. As this one's heart is twisted, in that he retains the thing that is incorrect - such that he is compared to a strainer, as it says.

the funnel: A vessel that is put at the opening of a barrel or at the opening of a pouch when one wants to fill it with wine or oil.

The sieve - because it lets out the [inferior] flour which is the incorrect argument; and does not retain it.

because it lets in at [one end] and lets out at [the other]: So [too], there is one who receives everything that he learns; [but] in the way that he absorbs it, so does he [relinquish] it.

and retains the fine flour meaning the correct argument - it retains it and does not lose it.

The strainer: He lets out all that he has heard in the House of Study and collects a wasteful matter.

The sieve: After we take out the bran and the bruised grain from the ground flour, the [inferior powdery] flour is left with the coarse fine flour, and [the latter] is the [more] important one; we pass it through a very fine sieve. And all of the [powdery] flour - which is like white dust - falls from it, and the coarse important flour remains. And so would they do with grain offerings. So [too], there is one who has the ability to separate and to cleanse his teachings and take the truth from the false and wasteful.