Shiluach HaKan: Why Must You Repeat the Mitzvah?

The shiur opens with a fundamental question on the language of shiluach hakan (sending away the mother bird): why does the Torah (תורה) use the double expression "shaleiach teshalach"? The Midrash Rabba in Ki Seitzei presents two possible interpretations: either it refers to the same bird returning multiple times, requiring you to send it away repeatedly, or it means that even after fulfilling the mitzvah (מצוה) once with one bird, you must still do it again when you encounter another nest. The shiur notes that the standard Talmudic language for such obligations is "afilu mei apamim" (even 100 times), which appears throughout Bava Metzia regarding hashavas aveidah and in other contexts. Yet here, the Midrash uses entirely different language: "shema teira lecha hamitzvah hazot pam shnia lo'omer kavar yatzasi yedei chovasi"—lest you think when this mitzvah presents itself a second time, you can say you've already fulfilled your obligation. Rabbi Zweig argues this unusual formulation indicates we're dealing with a different halachic principle than the standard "afilu mei apamim" cases. When the Gemara (גמרא) says "hasheiv teshiveim afilu mei apamim," it means if someone loses different objects—keys one week, an animal the next—you're obligated to return each one. Similarly, "hocheiach tochiach afilu mei apamim" means if someone commits different sins, you must rebuke him for each. The "afilu mei apamim" applies when the same person repeatedly loses the same object or commits the same sin, because we might think after three times the person is irresponsible (shoteh) regarding that item. But here the language suggests something different: perhaps without this doubling, one would think the mitzvah of shiluach hakan need only be fulfilled once in a lifetime, even when encountering entirely different birds and nests.