The 20th of Tevet is the anniversary of the death of Rabbi Moshe ben Maimon, also known as Maimonides or the Rambam (he died in Egypt in 1204).
Rambam was a great Talmudist, halakhist, doctor, philosopher, and community leader.
Among the writings of Rambam are a commentary on the Mishnah, the book Guide for the Perplexed, and a monumental compendium of laws called Mishneh Torah or Yad HaChazakah (the word iad In Hebrew, it corresponds to the number 14, which symbolizes the 14 books of the Mishneh Torah. Yad Hachazakah translates as "The Strong Hand.".
One interesting aspect of the aforementioned book of laws (Mishneh Torah) is that it contains all the laws of the Torah, even those that, due to the absence of a Temple, a King, etc., we cannot practically fulfill today. Most halakhic books focused on current practical laws, neglecting those that are impossible to observe. Maimonides codified all the laws, making it possible to study them all from a single source.
As Rambam himself writes in the introduction, "In general, so that a person does not need any other book at all on the laws of the Jewish people, but that this book gathers the entire Oral Torah, with the edicts, customs, and decrees made from the days of Moshe Rabbeinu until the compilation of the Talmud. That is why I called this book Mishneh Torah (second to the Torah) - because a person reads the Written Torah first, and then reads this book and knows from it the entire Oral Torah, and does not need to read any other book in between.".
One of the novel aspects of Rambam's halakhic work was his organization of Jewish law into fourteen books, which were further divided into topics, chapters, and laws.
Furthermore, this work includes all Jewish laws, both those that can be fulfilled today, and those that cannot (because we do not have a Temple, or a king, or for various other reasons).
In 1984, the Lubavitcher Rebbe established that this great work of Maimonides should be studied systematically, thus promoting the study of Torah in general, halakha in particular, and creating a system under which the entire Jewish people are united in studying the same subject at the same time, thus being able to discuss it in groups and exchange opinions.
Since the text is so long, the Rebbe established three systems of study, according to the possibilities of each individual:
1) An annual cycle of three chapters per day from the book Mishneh Torah.
2) A three-year cycle of studying one chapter per day of the Mishneh Torah.
3) An annual study cycle of the Sefer HaMitzvot (also available in Spanish, making Click here), where Maimonides briefly explains each of the 613 Mitzvot.
It is worth noting that he is the author of the "creed" of Judaism, the 13 principles of faith.
1) That God created and directs the world, He alone did, does and will do all things.
2) That God is not corporeal, bodily influences cannot reach Him, and nothing can compare to Him.
3) That God has no body or form.
4)That God is the beginning and eternity.
5) That God is worthy of making Tefilah and there is no one to ask besides Him.
6) That all the words of our prophets are true.
7) That the prophecy of Moshe Rabenu is true and he was the father of the prophets of all times.
8) That the Torah we have is the same one that was given to Moshe Rabenu.
9) That this Torah will not be changed and there will be no other from the Almighty.
10) That God knows everything the person does and knows all their thoughts.
11) That God rewards well those who fulfill His Mitzvot and punishes those who transgress His precepts.
12) That the Messiah will come. And even if he is delayed, we await his arrival every day.
13) That the dead will rise again when it is His will, praised be His name.
Hi Jorge, these 13 principles of Judaism, Maimonides writes them in his commentary on the Mishnah (cited in the article) as part of his introduction to the treatise Sanhedrin, that is, it is not an independent text, but a small part of another huge text.
There are some details in the text you posted that are confusing (principle 3 seems the same as 2, principle 4 is unclear, principle 6 is incorrect as stated, and principle 8 is not what Rambam says). Therefore, I will transcribe the 13 principles as Rambam wrote them (not a literal translation):
1) Existence of a Creator. Everything that exists needs Him to be, and He is the only entity that does not need anything else to exist.
2) The Creator is One, He cannot be divided nor is anything like Him in His essence.
3) The Creator has no body and nothing that happens in the material world affects him.
4) The Creator is Eternal, that is, all things except Him were created.
5) He is the only one who is to be served and prayed to, and all other creatures cannot do anything against His will, therefore, the Creator cannot be served through them.
6) Prophecy. Human beings can be prophets.
7) Moshe Rabbeinu possessed a level of prophecy superior to all other prophets in four aspects: he prophesied openly, without weakness, while fully awake, and whenever he chose. Therefore, Moshe attained a level of knowledge of the Creator superior to that of any other human being.
8) The Torah "comes from heaven." The five books of Moses were written by Moses at the dictation of the Creator; Moses did not write a single letter of his own understanding. The Oral Torah was also received at Mount Sinai and transmitted from generation to generation.
9) The Torah will never change, nor will any part of it.
10) The Creator knows the actions of human beings.
11) The Creator gives reward to those who observe the Torah and punishment to those who transgress it.
12) The coming of the Messiah from the house of David and he will be a king superior to all kings.
13) The resurrection of the dead.
Greetings!