The Shema
The Shema (Deuteronomy 6:4-9) is the central declaration of the Jewish faith, proclaiming the oneness of G-d. It instructs:
"And these words that I command you today shall be on your heart. You shall teach them diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise. You shall bind them as a sign on your hand, and they shall be as frontlets between your eyes."
These verses form the foundation for the mitzvah (commandment) of tefillin, symbolizing the binding of one's mind and actions to G-d's will.
Oral Torah
While the biblical verses command the wearing of tefillin, it is the Talmud that provides the detailed understanding and practical guidance necessary for its observance. Without the Talmud's explanations, the commandment would remain abstract and difficult to implement, as the Torah does not provide detailed instructions on how to fulfill this commandment, leaving many questions unanswered, such as:
- What are the tefillin supposed to look like?
- How should they be worn?
- What specific texts should be included within them?
- When and how often should they be worn?
The Talmud addresses these questions in detail. It explains why tefillin must be made of black leather and how they should be placed (Menachot 34b-35a), identifies the specific verses to be written inside (Brachot 6a), and clarifies the nature of their obligation (Kiddushin 34a).