In the school of Rav they say: One recites a blessing prior to performing all mitzvot, except for the ritual immersion after a nocturnal emission and the blowing of the shofar. The Gemara elaborates: Granted one does not recite a blessing prior to immersion, as this man who has not yet immersed is still unfit to recite a blessing because he is ritually impure. However, with regard to a shofar, what is the reason that one does not recite a blessing before sounding the shofar? And lest you say the reason is due to a concern lest the sounding of the shofar emerge flawed, and the blessing will be in vain, if so, one should not recite a blessing even prior to ritual slaughter and circumcision, as in those cases too one might fail to perform the action in the requisite manner.
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