Eruvin 2 - 8
“One who follows the stringencies of Beit Shammai and also the stringencies of Beit Hillel is described by the verse ‘and a fool goes in the darkness’ (Kohelet 2:14).”
Why is he called a fool and not pious for being strict, as taught in the above beraita in our gemara? Rashi (Eruvin 7a and Rosh Hashana 14b) offers an answer. The beraita is speaking about one argument based on one reason that has two halachic consequences: one lenient and one strict. A person who is strict in both halachot is a “fool” since he is contradicting himself by not showing consistency in following one reason throughout, and by not knowing to distinguish which reason is correct.
- Eruvin 6b
“Be careful in your work as a scribe, since your work is work of Heaven; perhaps you will omit a letter or add a letter and result in the destruction of the world.”
Rabbi Yishmael gave this advice to Rabbi Akiva on the importance of copying the Written Torah with utmost care. What is the “destruction” referred to by Rabbi Yishmael in omitting or adding a letter? Failing to write the letter aleph in “and the Lord G-d is true (emet)” would leave “met” meaning “dead”, and adding a vav onto the words “And G-d spoke” would turn the verb “spoke” into the plural form — implying two deities (Rashi).
- Eruvin 13a