“Who fulfills a mitzvah acquires an advocate; one who commits a transgression, you will earn an accuser.”
📖 Pirkei Avot 4:11

(1) the Identity and chronology

• Time: Late-first century / century II e.c., within the generations tanaíticas subsequent to the destruction of the Second Temple (70 e.c.).
• Homonyms: The rabbinic literature distinguishes between two different sages with the same name, to which much modern scholarship tends to call Eliezer ben Yaakov I and II. Its these appear scattered in the Mishnah, Tosefta, and midrashim halájicos; in several regions is not trivial to decide which correspond to each appointment.
• Distinctive feature: The sages of the Talmud say about him, the famous rating: “your Mishnah is kav naqee (little in quantity, pure/reliable in quality)”; hence the rule of thumb that when it appears his teaching in the Mishnah, is generally followed your opinion.

2) primary Sources where it appears

• Mishnah: Quotations and attributions in several orders (Zeraim, Moed, Nashim, Nezikín and Kodashim). It is particularly visible in treaties with theme of the Temple (e.g., Middot, Tamid), and in passages legal point where its formulation is brief but decisive.
• Pirkei Avot 4:11: Statement ethics classic to their name (see §6).
• Tosefta: Parallel and baraitot that amplify or attenuate their failures.
• Midrash halachic: Sifrá (Leviticus) and Sifré (Numbers/Deuteronomy) retain developments and powers.
• Talmudim: The Bavlí and the Yerushalmí cite his authority, discuss their scope and transmit the maximum “kav naqee”.

3) Profile and doctrinal theme

1. Precision and conciseness: Teachings relatively few, highly purified; premium clear statement on the case extensively.
2. Institutions of the Temple and Jerusalem: Action, access, perimeter, tours of priestly service, and ordinances related to the sanctity of space.
3. Standards of public conduct and reverence: Rules on external forms of piety, respect for sacred places and behaviors that preserve the dignity ritual.
4. Trend to rules that are memorable: In ethics, formulates principles short and pedagogical (v. §6).

4) the Main lines halájicas (representative samples)

• Topography and measures sacred (Middot/Tamid): descriptions of walls, patios, doors and tours in the Temple; these notes are used by the halachah later, and by the historical research/arquelógica to reconstruct the floor of the Sanctuary.
• Protective fences (gezerot): opinions that establish safeguards to avoid transgressions around sacred places or behaviors of modesty.
• Public order, religious (tzeniut of-rabbánan): guidelines on how and when perform certain practices in order to not induce confusion or lack of respect (e.g., pass behind a prayerful, behaviors around the synagogue, etc).
• Marital status and repairs (Nashim/Nezikín): failure point —not many— about marriage, witness and damage, where its formulation stark is registered and is sometimes preferred because of its clarity.

A rule of thumb is transmitted by the amoraím: “When the Mishnah brings to R. Eliezer b. Yaakov, the halachah is usually to follow” supported in the phrase of kav naqee. This rule is not absolute, but guides the poskim medieval when there is most explicit in against.

“Repentance and good works are a shield against misfortune.”
📖 Pirkei Avot 4:11

5) Method and style

• Sober language and technical: avoid ornamentation; the phrase is functional to the standard.
• Institutional memory- preserves details that reflect practice viva of the cult and of the holy city after the destruction.
• Rigorous selection: its legacy is relatively briefprecisely because it transmits only what it considers to be tested.

6) Highest ethical (aggadá)

• Pirkei Avot 4:11: “Rabbi Eliezer ben Yaakov says: he who fulfills a mitzvah is sought to be a defender (מליץ יושר); one who commits a transgression seeks an accuser (קטגור). Repentance and good works are like a shield against misfortune...”
  Conceptual axis: actions generate spiritual consequences real; that ethics is not merely inland, but performative.
• Other statements attributed to stress caution, respect for the Tefillah and the personal responsibility.

7) Teachers, peers and disciples

• Environment generation: linked circles R. Akivá and other wise men of the third/fourth-generation tanaítica.
• Partners faq: appears in opposition or complementary to R. Meir, R. Yehuda, R. Yose, among others, which located its activity in the arc post-Yavne (after Rabban Yochanan ben Zakai and Rabban Gamliel of Yavne).
• Rear transmission: amoraím as Rav and Shmuel already cited by the maximum kav naqee and treat your failures as firm when listed in the Mishnah.

“Silence is a wall of wisdom.”

8) Reception medieval and weight regulatory

• Geonim and Rishonim (Gaon of Sura/Pumbedita, Rif, Rambam, Rosh) collected numerous occasions where, if the Mishnah brings to R. Eliezer b. Yaakov without opposition conclusive, is bow by his posture.
• Mishné Torah (Rambam) and the codes later (Tur, Shulchan Aruch with its commentators) incorporate their opinions where they are guideline clean to fail.

9) History of textual and critical

• Variants: in manuscripts of the Mishnah and Tosefta (Kaufmann, Parma, Erfurt), your name may be abbreviated (“ר׳ אליעזר ב׳ יעקב”), which requires compare witnesses.
• Critical editions: appliances Hanoch Albeck, Chanoch Y. Albeck (ed. Mishnah), and Theodor-Albeck in Sifrá help you to separate layers and detect tweens, or attributions are dubious.
• Identification-I/II: in the passages discussed, the criteria to decide which include internal chronology, network of partners and terminology.

“The man must be conducted with modesty in all things, even in what is hidden.”
📖 Talmud Bavli, Berachot 62a

10) Input characteristic (synthesis)

• Standards for high reliability- few voices, a lot of force.
• Memory of the Temple: retains details that, without him, would have been lost.
• A bridge between halacha and ethics: its maximum in Avot return existential enforcement.

11) List of suggested passages useful for the study

• Pirkei Avot 4:11 – ethical maxim quoted above.
• Mishnah, Middot and Tamid – notes structural Temple, attributed to R. Eliezer b. Yaakov.
• Mishnah and Tosefta (Moed/Nashim/Nezikín) – failure point with your signature.
• Bavlí (e.g., Yevamot, Ketubot, Zevajim) – discussions where we setpoint “Mishnas R. Eliezer b. Yaakov kav naqee” and examines its scope.
• Midrash halachic: Sifrá and Sifré – parallel and developments of their positions.

12) Glossary minimum

• Kav naqee (קב נקי): literally “a kav (as) clean”: corpus brief but polished; without slag.
• Gezerá (גזירה): fence/safeguarding rabbinical for prevent violations of the Torah.
• Tzeniut (צניעות): and guard their modesty; here, modesty rules in public and ritual.

“The divine presence rests where there is purity and discretion.”
➡ Ethical tradition stemming from its line of thought, preserved in Derech Eretz Zuta (1:2)

13) references and recommended resources

• Encyclopaedia Judaica, s. v. Eliezer b. Jacob (I and II): state of the art, references and distinction of sources.
• Hanoch Albeck, Introduction to the Mishnah; ed. critical Mishnah Albeck.
• Theodor–Albeck, ed. critical Sifrá (Leviticus).
• Shmuel Safrai & al., The Literature of the Sages (Compendium of scholarship on Tannaim and Amoraim).
• Sefaria.org (for rapid consultation of primary sources, translations, and reference devices).
• J. N. Epstein, Introduction to the Tosefta (methodology for powers).
• Maimonides, Mishné Torah (locate where to follow their advice).

Conclusion

Rabbi Eliezer ben Yaakov embodies the ideal tanaítico of little word, and great authority. His legacy —especially in institutions of the Temple, conduct public religious and ethical principles in a nutshell— obtained in the tradition of a presumption of validity: “your Mishnah is kav naqee”. For a systematic study, it is appropriate to: (i) from Pirkei Avot 4:11, (ii) to map their appearances in Mishnah/Tosefta with the help of critical editions, and (iii) follow the trace amoraica where was made the rule-of-thumb in your favor. With this tripod, his figure looms sharp: a wise line brief and clean with a weight regulatory far exceeded the volume of their words.

“The measure of a man is known by his silence than by their words.”

“The truth does not multiply; you are debugging.”