Translation:Mishnah/Seder Nezikin/Tractate Avot/Chapter 2/1

Introduction
This Mishnah presents sayings of Rabbi Yehuda haNasi, called simply “Rabbi” or “Rebbi,” the son of the Rabban Shimon ben Gamliel of Mishnah 1:18. Yehuda haNasi was a leader of the Jewish community of Judea toward the end of the 2nd century CE, during the occupation of the Roman Empire. He is credited as the principal redactor of the Mishnah.

Hebrew Text
רַבִּי אוֹמֵר: אֵיזוֹהִי דֶרֶךְ יְשָׁרָה שֶׁיָּבוֹר לוֹ הָאָדָם? כֹּל שֶׁהִיא תִפְאֶרֶת לְעוֹשֶׂיהָ, וְתִפְאֶרֶת לוֹ מִן הָאָדָם.

וֶהֱוֵי זָהִיר בְּמִצְוָה קַלָּה כְּבַחֲמוּרָה, שֶׁאֵין אַתָּה יוֹדֵעַ מַתַּן שְׂכָרָן שֶׁל מִצְוֹת. וֶהֱוֵי מְחַשֵּׁב הֶפְסֵד מִצְוָה כְּנֶגֶד שְׂכָרָהּ, ושְׂכַר עֲבֵרָה כְּנֶגֶד הֶפְסֵדָהּ.

וְהִסְתַּכֵּל בִּשְׁלשָׁה דְבָרִים, וְאִי אַתָּה בָא לִידֵי עֲבֵרָה: דַּע מַה לְּמַעְלָה מִמְּךָ: עַיִן רוֹאָה וְאֹזֶן שׁוֹמַעַת, וְכָל מַעֲשֶׂיךָ בַּסֵּפֶר נִכְתָּבִין.

English Translation
 Rabbi [Yehuda haNasi] said: Which is the right path that a person should choose for himself? Whichever [path] that is [itself] an honor to the person adopting [it], And [on account of which] honor [accrues] to him from [other] people.

And be as careful with a light commandment as with a weighty one, For you do not know the reward given [for the fulfillment] of [the respective] commandments. Also, weigh the loss [that may be sustained through the fulfillment] of a commandment against the reward [that may be obtained] for [fulfilling] it, And [weigh] the gain [that may be obtained through the committing] of a transgression against the loss [that may be sustained] by [committing] it.

Keep your eye on three things, and you will not come into the grip of sin: Know what is above you: An Eye that sees, And an Ear that hears, And all your deeds are written in a book. 

Explanation
For commentary on Mishnah 2:1, see, for example:
 * The Maharal
 * Rabbi Menachem Schneerson
 * Yanki Tauber

משנה אבות ב א