"Our sages teach us that at the time of the Brit Milah, prayers can reach a place higher than the Shofar blasts of Rosh Hashanah..." (Original source unknown.)
From Minhagim, Amsterdam, 1707
1. The shofar is likened to the cries of a newborn child, one of the reasons it is sounded to mark a newborn year.
2. We are commanded to sound shofar in our times of joy, and what could be more joyous than welcoming a child to the covenant?
3. Shofar awakens us to the moment. Here is how one mother describes the brit bat of her twin daughters:
"After shacharit, the morning prayer service, we blasted the Shofar to announce the babies’ arrival and the brit they were about to enter, like the Israelites sounded* the Shofar before receiving the Torah. The sound of the shofar brought the crowd to attention, focusing them on the spiritual task of the day, just as it calls us to attention on the High Holidays. The call of the shofar was spine-tingling, adding some of the primal excitement felt at a brit milah into our brit bat."4. Brit milah and shofar are both psychically linked to the Akedah.
Our prayers say, “Z’chor bris Avraham v’ Akeidas Yitzchak”, remember the bris of Abraham and the binding of Isaac," - the bris milah corresponds to the bris of Avraham; the shofar to Akeidas Yitzchak - the binding of Isaac. Here is how another mother describes the commitment it takes, as a modern Jew, to fulfil the mitzvah of circumcision:
"I stood in our shul, weak winter sunlight coming through the stained glass windows, the front pews filled with our friends and family members, and suddenly felt my knees buckle as the mohel started his work on my brand-new boy... For me, it was a moment of unanticipated reckoning as a Jew. I suddenly felt like Abraham, exposing the tenderest parts of my treasure, my first born, to a knife — all because God had required it of me. His bris felt like the Akedah."5. Sounding shofar at a brit milah reminds us of the covenants into which we bring the child.
The covenant at Sinai was made manifest as the voice of shofar grew louder and louder. As I have described in Hearing Shofar: The Still Small Voice of the Ram's Horn," shofar can also be linked to other covenants, such as the one signified by the Rainbow and that made after the Akedah.
6. Shofar is symbolic of a circumcised penis.
The phallic nature of horns is frequently noted. Yet there is an additional similarity between a circumcised penis and a horn that has been transformed into a shofar. In both instances, it is a covering that is trimmed: the foreskin of the penis and the sheath that covers the bone core of a horn.
7. Shofar links circumcision to the annual blowing of shofar in the final moments of Yom Kippur.
Marking the covenant upon a man's genitals is a reminder that sexuality, too, is part of holiness. Verses about sexual morality are among the traditional afternoon readings during Yom Kippur (Leviticus 18), and Kabbalists explain that Tikkun Brit - the repair of sexual immorality - is central to the the Day of Atonement. Blowing shofar during a brit milah links a boy to the annual reminders about sexuality that he will, we trust, hear as a man during a lifetime of Yom Kippurim.
* I believe the author meant to say before "hearing" shofar.