Rosh Hashanah 7 - The month of Nisan
The month of Nisan is special in many respects; in particular, it is the first in the order of months. Why? - Since the Torah said, " This month will be for you the first ... take a lamb for each household," we know that the Exodus happened in the first month. But how do we know that it is Nisan? - Because the Torah also said, " Watch the month of the first ripened produce, " and this must be the spring month of Nisan. But perhaps it is Iyar, which immediately follows Nisan and which which you also have ripened produce? - No, it could not be Iyar, because "the first ripened produce" grows before. Then say that it is Adar, which precedes Nisan? - Also no, because we need the majority of "the first ripened produce." So you proof is based on that? - But did the Torah say "majority of the first ripened produce?" - No, it is did not. Thus, this proof is abandoned, and the Talmud starts another.
The other proof also does not succeed, and we are forced to admit that there is nothing in the Torah that tells us that Nisan is indeed the first of months. Instead, we resort to the books of the Prophets and say that really Nisan was always known to be the first, but that this knowledge was transmitted from teacher to student and not recorded anywhere in the Torah. Then came the Prophets and recorded it in conjunction with something else. For example, Ester was taken to king Achashverosh in the month of Tevet, which is called the tenth month. If so, then Nisan, which occurs nine months before, must be the first.
An extra month is added a year, when needed - always before Nisan; money is taken for new sacrifices in Nisan; and some say that Nisan starts a year for house rentals.
Art: Esther before Ahasuerus By Giovanni Andrea Sirani