Day of Judgment
Rosh Hashana is the day of judgment for all humankind. On this day man is judged as to the events of his life during the forthcoming year. (Talmud, Rosh Hashana 8)
It is the way of the world that if a person has a judgment pending against him, he dresses in black, wraps himself in black, lets his beard grow for the uncertainty of the outcome. Israel, however, is different. They dress in white; they eat, drink and rejoice, in the knowledge that G-d will perform miracles on their behalf. (Jerusalem Talmud, Rosh Hashana, ch. 1)
Sounding the Shofar
The sounding of the shofar contains an allusion: Awake you sleepers from your sleep, and you slumberers, arise from your slumber--examine your deeds, repent and remember your Creator. Those of you who forgot the truth in the vanities of the time and dwell all year in emptiness, look into your souls, improve your ways and actions..." (Maimonides, Hilchot Teshuva, ch. 3)
Rabbi Saadia Gaon gives ten reasons for sounding the shofar on Rosh Hashana, among them: At the beginning of a reign, it is customary to sound trumpets before the newly crowned king, and to proclaim his ascent to sovereignty throughout the realm. Similarly, do we accept anew the Creator’s sovereignty upon ourselves each year on Rosh Hashana. Also, sounding the shofar on Rosh Hashana causes us to recall our faith in the future resurrection of the dead. As it is said: “All you inhabitants of the world, and you who dwell in the earth; when an ensign is lifted on the mountains you will see, and when the shofar is sounded you will hear.” (Isaiah 18)