אם אין אני לי מי לי If I am not for me, who will be for me? Pirkei Avot 1,14

(יד) הוּא הָיָה אוֹמֵר, אִם אֵין אֲנִי לִי, מִי לִי. וּכְשֶׁאֲנִי לְעַצְמִי, מָה אֲנִי. וְאִם לֹא עַכְשָׁיו, אֵימָתַי:

(14) He [Rabbi Hillel] used to say: If I am not for me, who will be for me? And when I am for myself alone, what am I? And if not now, then when?

source #1

(יד) אם אין אני לי אם אין אני זוכה לעצמי מי יזכה בשבילי:

(14) ”If I am not for myself”: If I do not merit for myself, who will merit for me?

Bartenura is the name of the commentator who wrote a popular commentary on the mishna . His real full name is Ovadiah ben Abraham of Bartenura. Bartenura being a name of a place i Italy where he was born.

(יד) וכשאני לעצמי ואפילו זכיתי לעצמי, מה הוא הזכות הזה ובמה נחשב הוא כנגד מה שאני חייב לעשות:

(14) ”And if I am for myself”: And even if have merited for myself, what is this merit and what is it worth compared to what it is that I am obligated to do?

http://www.chabad.org/library/article_cdo/aid/2835298/jewish/Chapter-One.htm

QUESTION: How is it that Hillel, who was such a humble person (seeShabbat 30b), should talk about the importance of being concerned with one’s self?

source #2

ANSWER: Hillel is not talking about conceit and arrogance, but discussing the ugliness of selfishness and self-centeredness. He is therefore saying,“Im ein ani li — If when I do a favor to others, I do it altruistically and have no ulterior motives, and I do not calculate what will I ultimately gain from this, then mi li — who can say anything negative about me? However, if when I do a favor for others ani le’atzmi — I think of my selfish interest and benefits and otherwise I will not act, then mah ani — what kind of person am I considered to be? — someone of a little worth.”

(פניני אבות — תפארת ישראל)

source#3

Alternatively, Hillel is referring to a Jew’s performance of the 613 mitzvot of the Torah. When Moshe told the Jewish people about the giving of the Torah, they responded yachdav — together — and said, “Everything that Hashem has spoken na’aseh — we shall do” (Shemot 19:8). The Torah emphasizes that they responded yachdav — together — because it is really impossible for every Jew to perform all 613 mitzvot on his own. Somemitzvot can only be performed by a king, some by a Kohen, etc. Nevertheless, when the Jews are united, they are considered one entity. Thus, through togetherness, every Jew can receive credit for the fulfillment of all the 613 mitzvot.

Therefore, Hillel is stating, “If I am not for myself — but united with all ofK’lal Yisrael — then mi li — I can anticipate receiving credit for themitzvot I am unable to perform when they will be performed by others capable of doing them. However, keshe’ani le’atzmi — if I am only for myself — and there is no unity, mah ani — what am I? A Jew is required to fulfill all of the 613 mitzvot and I am not doing it.”

(ר' יחיאל מיכל זצ"ל מזלאצוב)