Mishnah 15 - Chapter 5 - Pirkei Avot

Arba middot beyoshevim lefenei chachamim. Sefog, umashpech, meshammeret, venafah. Sefog, shehu sofeg et hakkol. Mashpech, shemmachnis bazo umotzi vazo. Meshammeret, shemmotzi'ah et hayayin vekoletet et hashemarim. Venafah, shemmotzi'ah et hakkemach vekoletet et hassolet.

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.

There are four middoth (levels) in those who sit before the sages: [(Above, [Mishnah 12], the subject is remembering and forgetting; here it is logical reasoning and discriminating what is right from what is not right]: a sponge. [Just as a sponge absorbs muddy water together with clear water, so there is a disciple whose heart is "broad" and accepts whatever he hears, lacking the power to discriminate between the true and the false], a funnel, a strainer, and a sieve. A sponge — it absorbs everything; a funnel — it takes in at one end and releases at the other. [So, there is a disciple who emits whatever he absorbs]; a strainer — it releases the wine and retains the lees. [So, there is a disciple who releases whatever he has learned in the house of study and retains only idle talk]; and a sieve — it releases the flour and retains the meal. [After the bran and the bruised grain are extracted from the ground flour, and there remain the thin flour with the thick meal, the desired part, it is put through a very thin sieve, so that there descends all that thin flour, like a white powder, and there remains only the thick, desirable, meal. (This is how meal-offerings were prepared.) Similarly, there is a disciple who has the ability to sift what he has heard and to discriminate the truth from the false and the vain.]