Respectfully Quoted: A Dictionary of Quotations. 1989.
If I am not for myself, who will be for me? And if I am only for myself, what am I? And if not nowwhen?
Aboth 1:14, saying of Hillel. Pirkay Avot, often known in English as the Chapters of the Fathers, is the best known of the books of the Mishnah, first part of the Talmud. Translations vary; that above is from Leo Rostens Treasury of Jewish Quotations, p. 459 (1972).