The command to blow the shofar comes from the Torah, but no explanation is attached. Rabbis have provided different reasons. It acts as a reminder for the soul to enter into repentance. It is also a warning to the Jewish people not to fall into temptation. It calls to mind the blasts blown by Moses when he ascended from Mount Sinai for the second time, after pleading with G-d for mercy for the Jews who had worshipped at the alter of a false God.