הלכה אויף שמות 19:16

We may not mention malkhiot, zikhronot and shofarot of punishment — such as [in] zikhronot, "And all flesh shall remember that, etc." (Psalms 78:39); [in] malkhiot, "with outpoured anger shall I rule over you" (Ezekiel 20:33); [and in] shofarot, "Blow the shofar on the mountain, etc." (Hosea 5:8). Nor [may we mention] the remembrance of an individual — even if it was for good — such as "Remember me, O Lord, in the desire of Your people" (Psalms 106:4); and "Remember me, my God, for the good" (Nehemiah 13:31). And recollections (pikdonot) — such as "I have surely recalled you" (Exodus 3:16) — are not the same as remembrances. But one may mention the punishment of idolatrous nations, such as "The Lord reigned, nations tremble" (Psalms 99:1); "Remember the day of Jerusalem to the Children of Edom" (Psalms 137:7); [and] "the Lord, God, will blow with the shofar, and go in the storms of the south" (Zechariah 9:14). All of these verses: "Hear Israel, the Lord, our God, the Lord is one" (Deuteronomy 6:4); "You have been shown to know" (Deuteronomy 4:35); "And you shall know today and place upon your hearts, etc." (Deuteronomy 4:39) — their content is kingship. Even though there is no mention of kingship [in them], it is surely like, "The Lord will reign forever and ever" (Exodus 15:18); [and] "And then He became King in Jeshurun, etc." (Deuteronomy 33:5).

Rav Saadia Gaon writes that there are 10 reasons why the Exalted Creator commanded us to blow the shofar on Rosh Hashana. 1. This day is the beginning of creation when God created the world and ruled over it. At the beginning of a king's reign, they sounds the trumpets and shofars, to promulgate in all locations that the new reign has begun; likewise, we accept upon ourselves God's reign on this day [by sounding the shofar]. This is also why King David said (Ps. 98:6) "with trumpets and the blast of the horn raise a shout before Ad-nay, the King".2. Rosh Hashanah is the 1st of the 10 Days of Teshuva, and we blow the shofar in order to announce that all those who wish to do teshuva, should do so, and if not, there is no excuse. This is like what the kings do, that warn the people regarding a decree, and whoever transgresses the decree after the warning has no claim. 3. The shofar reminds us of the shofar at Mt. Sinai, when we accepted the Torah, as it is written "and a very loud blast of the shofar" (Exodus 19:16), and our ancestors accepted upon themselves "we will do and we will listen" (Exodus 24:7). 4. The shofar reminds us the words of the Prophets, who are compared to the tekiot of the shofar, as it is written " If anybody hears the sound of the horn but ignores the warning, and the sword comes and dispatches him, his blood shall be on his own head. Since he heard the sound of the horn but ignored the warning, his bloodguilt shall be upon himself; had he taken the warning, he would have saved his life." (Ezekiel 33:4-5). 5. The Shofar reminds us of the destruction of the Holy Temple and the cries of war, as it is written "Oh, the walls of my heart! My heart moans within me, I cannot be silent; my soul hears the teru'ot of war." (Jeremiah 4:19). When we hear this sound, we will beseech God to rebuild the Temple. 6. The shofar reminds us of the Binding of Isaac, who was ready to give his life for the sake of Heaven; likewise, we should also dedicate ourselves to sanctifying His name, and He will surely recall us for the good. 7. When we hear the sound of the shofar, we will tremble, be in awe and see our brokeness. This is the nature of the sound of the shofar, it causes one to tremble with trepidation, as it is written "When a ram’s horn is sounded in a town, do the people not take alarm?" (Amos 3:6). 8. The shofar reminds us of the ultimate Day of Judgment, as it is written "The great day of Ad-nay is approaching, approaching most swiftly... a day of shofar blasts and alarms" (Zephaniah 1:14-16). 9. The shofar reminds us of the Gathering of the Exiles when the shofar will be sounded, and this causes us to yearn for that time, as it is written "And in that day, a great ram’s horn shall be sounded" (Isaiah 27:13). 10.The shofar reminds us to believe in the resurrection of the dead, as it is written "all you who live in the land, and inhabit the earth, when a flag is raised in the hills, take note! When a ram’s horn is blown, give heed!" (Isaiah 18:3).