Chapter 2, Mishna 1:
Rabbi [Yehuda HaNassi] said: Which is the right path for a man to choose? That which is glorious to the one who walks in it, and brings glory from man. Be as careful in [performing a seemingly] minor mitzvah as of a major one, for you do not know the reward given for the mitzvot. Consider the loss [brought about by the performance] of a mitzvah agains the reward [earned by its observance], and the gain [derived] from a sin against the loss [that will follow]. Think about three things and you will not come to sin: Know what is above you - an Eye that sees, an Ear that hears, and [that] all of your deeds are recorded in a Book.
