Thus, you too shall lift up the offering from the grain ('terumah') to G-d (18:28)
From the words "you too" we derive that a person's agent can act in his stead; that "the agent of a person is as he himself."
- The Talmud, Kedushin 41b
When his eldest son, DovBer, reached chederage, Rabbi Schneur Zalman of Liadi approached one of his colleagues, a fellow disciple of their late Master, the Maggid of Mezeritch. In his characteristic singsong manner, Rabbi Schneur Zalman said:
"I have a mitzvahto fulfill - the commandment "you shall teach them (the words of Torah) to your children".1You, too, have a mitzvahincumbent upon you - the duty to support your family. Let us make an exchange: I will provide you with the means to fulfill your mitzvah, and you will teach my son Torah."
Rabbi Schneur Zalman then gave the young man a crash course in his approach to early childhood education: "One obviously starts with the Aleph-Bet. What is an Aleph? A dot above, a dot below, and a line in between - this is an Alef. And this is the very Alefof Torah: that the Yudabove (G-d) and the Yud2below (the Jew) are bound by a line of faith."
