Two Aspects Of Rosh Hashana

The Rambam Sefer Hamitzvot #170 says the mitzvah of shofar is to hear the shofar on the first day of Tishray.  He opens the Laws of Shofar by saying the mitzvah is to hear the shofar on Rosh Hashana.  Why does he switch terminoligy from the first of Tishray to Rosh Hashana? 

The Rambam if Teshuvah (3:4) says that blowing the shofar is a גזירת הכתוב but nonetheless there is a message in it which is to wake up and repent.  The Briskor Rav said the source for the Rambam is the verse in Psalms (91:5) כי חק לישראל הוא משפט לאלקי יעקב.  We see there are two aspects to the shofar, it is both a חק and a משפט.  What is the nature of these two aspects of shofar? 

In Parshas Pinchas (29:1) it says  וּבַחֹ֨דֶשׁ הַשְּׁבִיעִ֜י בְּאֶחָ֣ד לַחֹ֗דֶשׁ מִֽקְרָא־קֹ֙דֶשׁ֙ יִהְיֶ֣ה לָכֶ֔ם כׇּל־מְלֶ֥אכֶת עֲבֹדָ֖ה לֹ֣א תַעֲשׂ֑וּ י֥וֹם תְּרוּעָ֖ה יִהְיֶ֥ה לָכֶֽם, the day being a holy day precedes the commandment to blow shofar.  On the other hand, in Emor it says  דַּבֵּ֛ר אֶל־בְּנֵ֥י יִשְׂרָאֵ֖ל לֵאמֹ֑ר בַּחֹ֨דֶשׁ הַשְּׁבִיעִ֜י בְּאֶחָ֣ד לַחֹ֗דֶשׁ יִהְיֶ֤ה לָכֶם֙ שַׁבָּת֔וֹן זִכְר֥וֹן תְּרוּעָ֖ה מִקְרָא־קֹֽדֶשׁ, the commandment of shofar precedes that of establishing the day as a holiday.  Why the change?

The Ramban in Emor notes that the reason for blowing the shofar is not given in the Torah: ולא פירש הכתוב טעם המצוה הזאת, למה התרועה, ולמה נצטרך זכרון לפני השם ביום הזה יותר משאר הימים, ולמה יצוה להיותו מקרא קדש, אבל מפני שהוא בחדשו של יום הכפורים בראש החודש נראה שבו יהיה דין לפניו יתברך, כי בם ידין עמים, בראש השנה ישב לכסא שופט צדק, ואחרי כן בעשרת הימים ישא לפשע עבדיו, רמז הכתוב הענין כאשר נודע בישראל מפי הנביאים ואבות קדושים.  The Maharal in Teferes at the end of ch. 27 adds that the Torah never mentions Rosh Hashana as a day of judgement because that is not a reason that people will feel is worthy of celebrating.  In this verse when the Torah is alluding to the judgement of Rosh Hashana, the obligation to blow shofar is not a ressult of it being a מקרא קודש, hence it precedes the מקרא קודש in the possuk.  This obligation of shofar is a result of it being the first day of Tishray.  In Pinchas, where there is no mention of זכרון, there is no hint to the judgement, it is just a festive day to blow horns, that is an outgrowth of the מקרא קודש, it is a mitzvah of Rosh Hashana ,the holiday.  

We see from here there are two aspects to Rosh Hashana.  It is both a festive day worthy of celebrating, part of the set of holidays, and a day of judgement, worthy of being scared.  These two aspects are reflected in these two pessukim of shofar.  That is why there is much debate in the authorities as to if one may fast on Rosh Hashana, the question being as to which aspect of the day has the upper hand.

The מהרי"ל in siman 33 brings an opinion that one should not do תוספת ראש השנה by eating early on Rosh Hashana because it is a day of judgment.  The Maharil points out that he does not know whatthey are gaining because they davened early and hence accepted the day early anyway.  However, in light of this, we can understand that one can do תוספת ראש השנה for the holiday aspect of Rosh Hashana and not for the judgment aspect.  By davening early, they accepted the holiday oכ Rosh Hashana early, but did not bring upon themselves the day of judgment.  (Based upon Rinas Yitzchak to Nach Tehillim, Shoalin V'dorshin volume 7, see also T'shuvot V'hanhagot volume 4 #101.)