The first Mishna on our daf teaches that a person must take great care in leaving sharp objects in places where they can cause damage or injury. For example, if a person builds his fence out of thorns or places shards of glass in a fence, he will be responsible for any injuries that take place.
This teaching leads our Gemara to bring a baraita that teaches about Hasidim ha-rishonim – early groups of particularly pious people – who would make sure to bury their thorns or broken glass three tefahim deep in their fields so that they would not cause damage even to plows. The Gemara relates further that Rav Sheshet made sure to burn his, while Rava threw his into the Euphrates. Rav Yehuda concludes this discussion by saying that someone who wants to become pious should take great care regarding the laws of nezikin. Rava says that he should keep the rules enumerated in Massekhet Avot, and some say he should keep the laws of Berakhot.
The Rashba and Rabbeinu Yehonatan suggest that these three sets of rules are quoted because we find in each one of them specific references to how pious Jews are supposed to act. The Maharsha explains this Gemara by describing three levels of human perfection, each of which can be attained by the study and application of different sets of religious texts. These levels are:
- Tov la-Shamayim – someone who strives for a perfect relationship with God – must study the laws of Berakhot;
- Tov la-beri’ot – someone who is good to his fellow man – must study the laws of nezikin;
- Tov le-atzmo – someone who seeks peace with himself – must study the teachings of Massekhet Avot, which teaches how to attain spiritual perfection.