As Teitelbaum explains in the introduction, the book's title is taken from the biblical verse of Exodus 2:21, and hints to Teitelbaum's first name (Yoel), and to his grandfather, Moshe Teitelbaum. The verse, which states "And Moses agreed to stay...an alien in a foreign land", hints to Teitelbaum's conclusion that the Jewish people should remain in exile.
The book is considered to be Teitelbaum's magnum opus, and is of the utmost importance to Satmar Hasidim, as well as to many Haredim who follow the Satmar doctrine regarding Zionism. Satmar Hasidism has many institutions, buildings and neighborhoods named after the book.
Vayoel Moshe is primarily a book of Halacha, Jewish law. However, it draws on Rabbinic Jewish philosophy as well.
The book consists of three parts:
1. Maamar Shalosh Shevuos (Treatise regarding the Three Oaths), which is the main part of the book, is an in depth analysis of the Three Oaths and their practical halachic implications.
The "Three Oaths" are originally detailed by the Talmud in tractate Ketubot. The Talmud discusses a passage from the Song of Songs in the Tanakh (Hebrew Bible) in which God made the Israelites promise "to wait for Him before arousing his love" as "King Solomon in Song of Songs thrice adjured the daughters of Jerusalem not to arouse or bestir the love until it is ready." The Talmud explains that the Jewish people are bound by three oaths:
The Talmud follows the discussion of the oaths with a strong warning:
...Rabbi Elazar said: The Holy One, Blessed be He, said to the Jewish people: If you fulfill the oath, it is good, and if not, I will abandon your flesh and all will devour you like the gazelles and like the hinds of the field.
Teitelbaum discusses the legal status of the oaths and what they imply. He argues that while the oaths are clearly metaphorical, and do not have the legal status of actual oaths, they are to be understood as guidelines for what is considered to be an attempt to leave exile before divine redemption, which he posits is severely forbidden and is tantamount to heresy.
2. Maamar Yishuv Eretz Yisroel (Treatise about settling the Land of Israel), which seeks to clarify if there is a halachic obligation to dwell in the land of Israel, as well as general halachic concerns regarding Jews emigrating to Israel, known as Aliyah.
3. Maamar Leshon HaKodesh (Treatise about the holy tongue), in which Teitelbaum writes that not only is there no reason to choose to speak Modern Hebrew, it is actually forbidden. This was written as a personal answer to the chief rabbi of Montreal at the time, Rabbi Pinchas Hirschsprung, and it was later added into this book.