All Esrogs grow with a pittum but many fall off as it grows. If the pittum falls off after it is harvested it is invalid. If a little bit of wood of the pittum remains it may be used.
If any part of the stem of the Esrog is missing it is invalid to be used on the first day of Sukkos. The same is true if any part of the flesh is missing (see Laws #3). On the second day of Sukkos, if a small part of the flesh or stem is missing it may be used.
There are three layers to an Esrog; the glaze on the outside, the green/ yellow skin, and the white flesh. When purchasing an Esrog, one of the things to look for is if any of the flesh is missing. If it is, the Esrog cannot be used on the first day and therefore should not be purchased. It may take an expert to distinguish between the different layers and to ascertain if flesh is missing or if there is a discoloration.
The Sefer Hachinuch suggests another reason behind the Mitzvah of Lulav and Esrog. The holiday of Sukkos is described in the Torah as Chag Ha’asif, the festival of gathering, as the holiday coincides with the harvesting of one’s produce. The harvested produce would naturally bring great joy to the owners. The taking of the Lulav and Esrog is a way of channeling the self-joy we experience at this time and direct it to G-d. Additionally, celebrations can at times take a turn away from the spiritual. By utilizing the same items that we are ecstatic over, we ensure that our celebration will maintain a spiritual flavor.
Who can think of Sukkos? We haven’t even celebrated Rosh Hashana!
The Talmud instructs us to study the laws pertaining to a holiday 30 days before the holiday. It’s less than 30 days to Sukkos and the laws of Lulav and Esrog are complicated and many. So let’s begin!
Before we get into the what, let’s take a moment to discuss the why. There are a number of reasons suggested as to why we take the Lulav and Esrog on Sukkos.
The Rambam (in the Guide to the Perplexed) sees Sukkos as the culmination of the Exodus. As our ancestors traveled through the desert there were no trees or vegetation. Upon arriving in the land of Israel, the lush greenery overwhelmed them and made them immediately aware and grateful for the beautiful land that they were given. By taking the four species on Sukkos, species that were readily available throughout the land of Israel, we are reminding ourselves of the excitement our ancestors felt, and this in turn should inspire us to be grateful for the gift of Eretz Yisrael.