The Rama in Shulchan Aruch Orech Chaim in Siman 585 Se'if 2 says: It is good to blow the shofar on the right side of the mouth. Why is it good to blow the shofar on the right side of the mouth? The Magen Avrohom brings a pasuk in Zecharia: Vehasatan Omeid al yemino lesitno - and the Satan was standing on his right side to hinder him. Since the purpose of Tekias Shofar is to counteract the kitrug of the Satan, we should put the shofar on the right side of the mouth. This isn't to be understood literally that the Satan is standing on the right side, and what does it mean that the purpose of the shofar is to counteract the kitrug of the Satan? Chazal said Hu hayetzer hara, hu hasatan, hu hamalach hamaves. The Satan is symbolic of the evil inclinations in man. The basic destructive forces in human behavior - the evil inclination, the animal instinct - that make him run counter to all the moral principles of the Torah, that is the Satan. What does it mean that the satan was on his right side? The right side represents that which is regular. The left side represents that which is irregular, unusual. A person writes with the right hand. If something happens to the right hand, under extraordinary circumstances he will write with the left hand. The evil inclinations which operate within the human psyche are regular things. Satan doesn't operate only at certain times, he operates constantly.
The shofar symbolizes the obligation incumbent on all human beings to wake up from their spiritual coma. We have to be spiritually awake and not sink in a spiritual and moral slumber. That is why the shofar should be blown from the right side of the mouth - to symbolize we should be on guard every minute of the day and every minute of the night.
The Biur Halacha mentions the Or Sameach that actually it is a pasuk in Shoftim by the war of Gidon: Vayachaziku beyad smolam b'lapidim, uveyad yeminam hashofar liskoa.
The Rama continues: The shofar should be pointed up as the Pasuk says, "A teruah rose to Hashem" (Tehillim 47).A safek (doubt) arose as to what a teruah of the Torah represents. There is a teshuva of Rav Hai Gaon saying that it does not mean the Chachamim had a safek because it is a chiyuv on everyone to hear shofar once a year. How could a safek arise? Regardless, the Torah says: yom teruah which is explained as yom yevava. The yevava is a sound expressive of grief, and there are different sounds of grief. Really you are yotzei with whichever sound you heard, but there were chalukim in communities, so Rav Abahu instituted 3 sets of tekiah-shevarim-teruah-tekiah, 3 sets of tekiah-shevarim-tekiah, and 3 sets of tekiah-teruah-tekia. But really any of the 3 are good enough.
The pasuk says: yom zichron teruah. Rashi says that we need a beracha of zichronos which is commemorative of Akeidas Yitzchak, and tekias shofar is also commemorative of Akeidas Yitzchak. The Ramban asks on Rashi that from Rashi it appears that midioraysa we are obligated to say the beracha of zichronos. How can Rashi say this, because in the Gemara Rosh Hashana there is a case that if someone can go to one of two towns, and in one of the towns the berachos of Rosh Hashana are said, but the shofar is not blown, and in the other town the shofar is blown but the berachos of Rosh Hashana are not said, he should go to the town where the shofar is blown because hearing the shofar is midioraysa and the berachos are not. If Rashi holds the berachos are midioraysa, why doesn't the Gemara say to go to the town where they do say the berachos? Therefore the Ramban says that we do not have to say the pesukim of the akeida, but through blowing the shofar, we will arouse Hashem's remembering us. How can we answer the question of the Ramban on Rashi?
We can say that really the obligation of saying the berachos is midioraysa. And that which Rashi emphasizes the shofar should be blown during the berachos of malchios, zichronos and shofros teaches us not just that the shofar must be blown during the recitation of the berachos. The fulfillment of the obligation to say the berachos will not be complete without the blowing of the shofar. Therefore, the berachos are midioraysa, but the obligation won't be completely fulfilled without the coupling of the blowing of the shofar. But if he goes to the city where they blow the shofar, he will get a fulfillment of a mitzva midoraysa.
In regard to the mitzva of shofar, min haTorah we need three sets of tekiah-teruah-tekiah. The Netziv in Haemek Davar points out that in regard to Rosh Hashana, the Torah says yom teruah and zichron teruah, but never tekiah. He says that the teruah is expressive of grief, and the tekiah is an expression of joy. That is what the Torah means in Parshas Beha'aloscha (Bamidbar 10) Vechi savo'u milchama be'artzichem... vaharei'osem... Uvyom simchaschem... uskatem. The Netziv explains simply that the tekiah, an unbroken sound represents joy, contentment, happiness, prosperity. The teruah, a broken sound represents frustration, trouble, suffering, grief. So on Rosh Hashana, yom teruah, we must arouse ourselves. We shouldn't be contented with our spiritual status. It's true aizehu ashir hasomeach bechelko, but that is on a material level - a person should be happy even when he barely makes a living, but chas veshalom that a person should be complacent and happy with his spiritual lot. That is the source of all evil - complacency on a spiritual and moral level. A person should feel that he doesn't measure up to what is expected of him. The braysa in Nidda (this is the pekidah around which the entire Tanya by Reb Shneur Zalman revolves) says that when a child is born, he is told, "Even if everyone tells you are a tzaddik, you should feel like you are a rasha." This seems to contradict the mishna in Pirkei Avos, Al tehi rasha bifnei atzmecha. But if you are the Chafetz Chaim and everyone tells you that you are a tzaddik, that you have to consider yourself a rasha is inconsiderable. It means you should feel guilty. The Chafetz Chaim was never complacent or happy with his spiritual status. He always felt that he didn't measure up to that which was expected of him. That is what the braysa means. Don't feel complacent. That is the source of all crime and sin. He must feel he doesn't measure up to that which is expected of him. This is the purpose of the teruah: to arouse grief. To arouse a feeling of sadness over our own inadequacies.
That every teruah must be preceded and followed by a tekiah teaches us that while one must do teshuva, he shouldn't sink into a depression and feel, "What is the use of this? I'm lost anyway. I can't go back." Chas veshalom! This is a terrible feeling- I'm lost, it's hopeless. No one is lost no matter how wicked he's been. There is always the possibility to return to Hashem. He has to be determined to mend is behavior pattern. While he's obligated to arouse feelings of sadness and grief over his inadequacies and failures to adhere to the morality that Hashem instituted, he's not lost. He is the master of his own spiritual destiny. If he acts with determination and resoluteness to the effect that everything will be good as long as long as he's able to the effect that his life should be joyous and happy in the end, all's well that ends well. You need to blow a teruah indicating the grief that has to overtake us over our inadequacies and failure and sins. But at the same time, it must be preceded and followed by a tekiah, symbolizing that he can't sink into depression because it's man's nature to sin. Chas veshalom, we don't believe in the concept of original sin, that people are basically evil. That is the doctrine of umos ha'olam. We believe in the doctrine of original virtue. We say every day, "Elokai, neshama shenasata bi tehora he." Every person is born pure and sacred and then in contact with the environment and mingling with society he becomes contaminated. The teruah preceded and followed by a tekiah represents that if we act with determination and character, we can finalize our life also with an olam shekulo tov, olam shekulo aruch. This is the symbolism of tekiah-teruah-tekia. And according to Rashi, this is what must be coupled with the berachos of malchios, zichronos and shofros.
Now the Ramban's question that zichronos is derabanan, we answered that it's only dirabanan without being coupled with the blowing of the shofar. And the Ramban's other question - if Rashi holds it's not an asmachta, why does he emphasize zichronos and pesukim of the akeidah, and not the berachos of malchios and shofros? The answer s just as by shofar the Torah says yom teruah, the basic idea is the sound of grief that must arouse us with grief over our own sins, our own guilt, our own inadequacies and failure to comply with the precepts of the Torah, it must be preceded and followed by a tekiah which is symbolic of happiness because we should not chas veshalom sink into depression and think we can't do teshuva. We must feel it's never too late and we can mend our ways to change our status and change everything into an olam shekulo tov, here, too, is the basic idea of the beracha of zichronos. What does it represent? Being dedicated to the mandate of mesiras nefesh, and akeidas Yitzchak is the inspiring source that enabled Jews throughout the ages to be moser nefesh themselves. But don't think that being moser nefesh is the only thing. It must be coupled with malchios - we appoint the Ribbono shel olam as our King. A king represents an organized, coordinated order and we are making Hashem our King saying we must have life in conformity of an organized, coordinated, moral order instituted by Hashem in Klal Yisrael. And Shofros represents tekia-teruah-tekiah that in spite of all the trouble, in spite of all the suffering and all problems and frustrations that overtake man, it is within the power of man to change everything into good. Because there is so much "teruah" overtaking us, it is proceeded and followed by a tekiah. It is up to us to do teshuva. We are the masters of our own destiny on a spiritual and moral level. The nations of the world have an expression "Mind over matter." It is a basic truth, but in order to be mind, it must have characteristics of the mind, which is the source of consciousness. That is the beracha of zichronos. It represents that Hashem is zocher kol hanishkachos. How does it protect us? We have to be morally conscious. If we abandon the Torah, we sink into a spiritual and moral coma! Zichronos symbolizes we must retain spiritual and moral consciousness. Malchios represents that we have to lead a morally coordinated life that our behavior pattern conforms to a certain moral order that was promulgated by Hashem for us. Shofros represents tekiah-teruah-tekiah, that in spite of all the trouble, in spite of all the frustration and all the suffering, man's existence in its entirety, sometimes we can't understand it, but here is the main point: Vayar Elokim es asher asah vehinei tov me'od. In final analysis, in spite of all the trouble, in spite of all the sicknesses, frustrations and problems that overtake every human being, Jew and Gentile alike, vehinei tov me'od. That is the beracha of shofros.
Rosh Hashana doesn't only mean first day of the year, it means mind of the year. That on Rosh Hashana we must regain spiritual and moral consciousness in our minds, the source of consciousness. The mind is the coordinating factor in the human organism so our lives must be in accordance with the moral order instituted by Hashem. And the mind, in order to function properly, must not sink into depression. If one sinks into depression, he's like a vegetable.
This is the message of the shofar and the berachos of malchios, zichronos and shofros.
Please note: This shiur was transcribed by a talmid.