No sooner do we open the Torah, seeking to understand the significance of the day, than we are plunged into mystery. Only twice does the Torah touch on the subject, and in neither case does it provide much information:

The Lord spoke to Moses, saying: Speak to the Israelite people thus: In the seventh month, on the first day of the month, you shall observe complete rest, a sacred occasion commemorated with loud blasts [zikhron terua]. (Lev. 23:23–24) On the first day of the seventh month you shall hold a sacred assembly. You shall do no laborious work, and you shall mark a Day of the Blowing of the Shofar [Yom Terua]. (Num. 29:1)

Other than details of the sacrifices to be offered, that is all. There is no explanation of what the day represents, or what the sound – terua – signifies. Nor does the Torah specify what instrument is to be used. It might be a horn. But equally it might refer to the silver trumpets the Israelites were commanded to make to summon the people (Num. 10:1–10). The central motifs of the other festivals, the unleavened bread and bitter herbs of Pesaĥ, the booth of Sukkot, the affliction (fasting) of Yom Kippur, all have symbolic value. We know what they mean and how they connect with the mood of the day. But the Torah does not tell us what the sound of terua symbolizes. Is it the sound of celebration, of warning, of fear or tears? We do not know.¹, Rosh HaShana (2).

footnotes: ¹ Rabbeinu Baĥya, Kad HaKemaĥ

Nor does the Torah use the phrase Rosh HaShana, the beginning or “head” of the year, in this context or any other. The only time it appears in Tanakh, the Hebrew Bible as a whole, it refers to Yom Kippur: “In the twenty-fifth year of our exile, at the beginning of the year [berosh hashana], on the tenth of the month, in the fourteenth year after the fall of the city” (Ezek. 40:1). In fact the Torah seems to make it clear that Rosh HaShana is not the beginning of the year. It is the first day, not of the first, but the seventh month. The first month is Nisan.

How then do we arrive at the festival as we know it today?

In the earliest stages of an embryo, when a fetus is still no more than a small bundle of cells, it already contains the genome, the long string of DNA, from which the child and eventually the adult will emerge. The genetic structure that will shape the person it becomes is there from the beginning. So it is with Judaism. “Bible, Mishna, Talmud and Aggada, even what a senior disciple is destined to teach in the presence of his master, was already stated to Moses at Sinai” (Yerushalmi, Pe’ah 2:4). The evolution of Rosh HaShana was prefigured at the outset, but to see how it developed we have to decipher the clues.