The Mishnah (Niddah 51b) states that any fish that has scales certainly has a fin but there are fish that have a fins and no scales. So we can rely on scales alone to say that the fish is kosher even though he does not see its fins. If so why doesn’t the Torah only write the requirement of a kosher fish to have scales and omit the requirement of fins? The Tanna Rabbi Yishmael answers יגדיל תורה ויאדיר (Yeshaya 42,21) Hashem wants to teach you explicitly and He therefore expands the Torah and amplifies it.
The Kozhiklaver Rebbi R’ Tzvi Aryeh Frumer z”tl Rosh Yeshivah of Chachmei Lublin explains this answer with a novel interpretation repeated by the Tolna Rebbi Shilta at his Tu Bishvat Tish (Eretz Tzvi Yalkut Haemunah p.251). Where did the Chachamim have the knowledge to say such a blanket statement without any exception? Do you realize that at 32,000 species, fish exhibit greater specie diversity than any other group of vertebrates? How then could anyone have the audacity and the know all to conclude from the time of the Mishnah and up until the end of time that every fish that possesses scales automatically has fins? In the times of the Mishnah the world was not aware of the continent America up until Columbus. From America the world discovered the potato which was brought first to Europe. Could it not have been very possible that from the time of discovering America and potatoes, a new species of fish with scales and no fins would also be discovered? Yet from the beginning of time until this very day no exception to the Chachamim’s rule has been found. No, they were not marine geologists, nor were they professors of oceanography of all the oceans and seas. They were not trained to scuba dive, or use echo sounders, sonar imagery and submersibles. They only knew this knowledge from one source and that is our Holy Torah which is the blueprints of the world. If one is able to connect to the source which contains the blueprints from where everything evolved, he has on his fingertips the deepest wisdom of all existence.
Let us look at a more recent example of Torah World Knowledge, the Chazon Ish ztl who learned Torah Lishmah in a small shteeble in Kosava, Lithuania, was able to write a detailed diagram to a neurosurgeon on the procedure of how to remove a brain tumor which involved a very complex surgery. When the surgeon studied the diagram he asked in amazement at which university did this doctor of surgery study, he would very much like to meet him. There is a photograph of that sketch in existence today. When one learns Torah Lishmah Hashem grants him the knowledge of world. As we say in davening ונתן לנו תורת אמת וחיי עולם נטע בתוכנו by giving us the Torah of Emes, the secular knowledge and components of all life he implanted within us.
On Tu Bishvat we celebrate the renewal of the trees when the sap begins to ascend up from the roots and reawakens its dormant vitality. How did Chazal know that this is the definite date of this occurrence? They were not educated arborists who studied trees for many years. Nor did they have instruments to verify the exact date when this natural phenomenon happened. But what they did have was total dedication and immersion in the Torah which granted them that worldly knowledge to an incredible exact degree.
This is what is meant by the term להגדיל תורה ולהאדירה. The Torah wrote that the requirement for defining that a fish is kosher to eat is that it must have both scales and fins. From the Torah alone it seems that there is therefore the possibility of fish only having one kosher sign even if it is scales and not fins thereby rendering it non kosher. However, the Chachamim came and said, as long as you see scales you know already for sure that it must also have fins. By this incredible statement they demonstrated that the Torah is truly supernatural and one can know the wisdom of the universe through it. The proof is that this statement of the Chachamim has been authenticated without exception throughout the centuries up until this very day. Had the Torah only written that a fish is kosher as long as it has scales then it wouldn’t have allowed for us to have seen the greatness of the interpretations of our Chachamim who toil in learning Torah lishmah and their wisdom of the natural world.
Tu Bishvat is therefore a Yom Tov about the Chachamim who interpret the Torah through toil and diligence. It could very well be that the tree symbolizes the Aitz Hachayim which symbolizes the Written Law and Oral Law. That is why the Mishnah uses a singular term ראש השנה לאילן (Rosh Hashana 2). Chazal say that the Aitz Chayim symbolizes Torah as the passuk says עץ חיים היא למחזיקים בו. The Aitz part refers to the tree which represents the Written Torah, the source through which the fruit are sustained and nurtured. The Chayim part symbolizes the Chachamim who give life to the Torah. The gematriah of חיים is חכם .
Tu Bishvat is the Yom Tov when our emunas Chachamim and our learning of the Oral law is examined, for it is the day of judgment on the fruits of the trees.
Thirty days before the chag one must begin studying the halachos of the upcoming Yom Tov. Accordingly, on Tu Bishvat we begin learning the Laws of Purim. This means that Tu Bishvat and Purim have an inner connection together by this bridge of thirty days. The parallel between the two is the Oral Law. The Megillas Esther saysקיימו וקבלו היהודים upon which Chazal expound (Shabbas 88) that the Yidden on Purim received with love what before hand they accepted with fear. At Matan Torah Hashem placed the mountain Sinai over our heads and gave them the ultimatum to either receive the Oral Law or they will perish. They accepted it through fear of death. However on Purim they reaccepted the Oral Law through love. Both holidays are connected with the acknowledgment that without the Chachamim we would not realize the lofty heavenly wisdom of our holy Torah.