I might think that if the year were lacking fourteen or fifteen days, you should add that number of days to it; it is, therefore, written "the month," and not less....
I might think that if it were lacking forty or fifty days, you should add that number of days to it; it is, therefore, written "the month" — not less and not more.
(Devarim 16:1) "Observe the month of Aviv": In three places the section of festivals is mentioned: In Vayikra, because of their order;
We are hereby apprised that Moses heard the order of the festivals on Sinai, repeated it to Israel, and repeated it again at the time of their occurrence,