1. The Turei Even writes that although the Gemara derives from a verse that the Korbanos should be brought from the new donations, if they were brought from last year's donations, b'Di'eved the Korbanos are valid. This is because there is a rule with regard to Kodshim (see Pesachim 61a), "Shanah Alav ha'Kasuv l'Akev" -- the Korban becomes invalid b'Di'eved only when the particular requirement is stated twice in the Torah. If the Torah says this law only once, this teaches that it is only a Mitzvah l'Chatchilah but it is not Me'akev.

Accordingly, the Torah wants us to buy the Korbanos from the new donations, but if they were bought from the old donations, the Korbanos are valid b'Di'eved, and merely the Mitzvah l'Chatchilah was not done. One does not fulfill the Mitzvah of bringing the Korban from the new donations, but nevetheless the Korban is valid.

2. Support for the notion that the Korbanos must be brought from the new donations only l'Chatchilah may be found in another assertion made by the Turei Even, as cited by the Minchas Chinuch (Mitzvah 311:7). The Turei Even cites the Mishnah in Shekalim (4:5) which states that the Korbanos must be bought from the new donations only when those donations arrived on time. If they have not arrived in the Beis ha'Mikdash by Rosh Chodesh Nisan, then the Korbanos are bought from the old donations. This shows that, b'Di'eved, Korbanos bought from the old donations are valid (because, otherwise, it would not help to buy the Korbanos from the old donations when the new donations did not yet arrive).

3. The Pnei Yehoshua (Rosh Hashanah, end of 7b) suggests a slightly different explanation. When the Gemara states that a Mitzvah is lost, this means that the person did not perform a "Mitzvah Min ha'Muvchar" -- the choicest Mitzvah, but he nevertheless performed a Mitzvah by bringing the Korban. The Pnei Yehoshua justifies this interpretation by stating that the Derashah cited by the Gemara here, "l'Chodshei ha'Shanah" (Bamidbar 28:14), does not have the status of a positive commandment of the Torah, but rather the Torah is merely teaching the best possible way to bring the Korban.

However, in his conclusion, the Pnei Yehoshua rejects this explanation, based on the Gemara in Menachos (83b). The Gemara there uses the phrases, "If he brought it, it is Kasher," and, "Yatza, Ela she'Chiser Mitzvah," synonymously.

4. The Teshuvos Torah li'Shmah (#205, attributed to the author of the Ben Ish Chai) compares the Gemara here to the Mishnah in Yevamos (24a) which states that it is a Mitzvah for the oldest brother to do Yibum, but if a younger brother does it he also fulfills the Mitzvah. The Torah li'Shmah writes, however, that if the younger brother does the Yibum, there is a flaw in the Mitzvah itself. Similarly, if Korbanos are brought from the old donations, there is a flaw in the Mitzvah. In contrast, if one makes a Shali'ach to perform Bris Milah or to search for Chametz, the Mitzvah itself was not lacking at all, but the father of the son who knows how to circumcise or the owner of the house who could have searched for the Chametz merely lost the Mitzvah. (The Torah li'Shmah follows the conclusion of the aforementioned Pnei Yehoshua.)

Kol Tuv,

Dovid Bloom