Pirkei Avot is the section of the Mishnah that deals primarily with Jewish philosophy and ethical living. Here is the first part, with my literal translation from the Hebrew to accompany my following commentary.
Moses received Torah* from Sinai** and handed down*** to Joshua; Joshua to the Elders [of the tribes of Israel]; the Elders to the Prophets; the Prophets handed down to the men of the Great Assembly. They**** said three things: Be cautious in judgement***, raise up many disciples, and make a fence around Torah.** (Chapter 1, Mishnah 1)
* Many English translations incorrectly translate this as “the Torah.” The Hebrew word תורה (Torah) does not have the ה in front that would make it “the Torah.” But why did the original author not write “the Torah”? The inclusion of the definite article would make it sound like the Law has a finite existence, a beginning and an end. Torah is infinite. Like God, Torah itself is אין סוף (without end).
** Why does the Mishnah not say “from God” or “at Sinai” rather than “from Sinai”? This is to remind Jews that the giving of Torah occurred at a specific place and a specific time in history. It was a REAL event. It is not an oral tradition or a myth — it was an actual event at an actual place. All Jews, present and future, were there.
*** The Hebrew neither repeats the word “Torah” nor uses the pronoun את זה (it) when referring to the handing down of Torah through the ages. The use of the pronoun would give a sense of limit to Torah just like the article ה (the) would have done. See my first footnote.
**** The pronoun “they” refers specifically to the men of the Great Assembly and not collectively to Moses, Joshua, the Elders, and the Prophets as well. The Great Assembly was the first to make rulings and issue precepts based on Torah since knowledge had become diffused by that time.
*** Courts of law are to resemble God. Courts should be neither too strict nor too lenient; they should be fair. This resembles two aspects of God as described in the mystical tradition — דין (Judgement) and חסד (Mercy) — that are balanced by תפארת (Compassion).
** Jews are supposed to guard against even approaching the breaking of Torah. For example, it is forbidden in the Bible Talmud to eat beef and dairy products in the same meal. The Oral Law — the Talmudic tradition that accompanies the Written Law in the Bible — also expanded this prohibition to include chicken so Jews are one step removed from even coming close to violating the precept. (Fish is allowed.)
Note: Most of the commentary comes from tradition sources, but a few ideas are mine. Then again, there is nothing new under the sun.

