ציטירנדיקער פּירוש אויף תהילים 98:1

עזי וזמרת י-ה, “G’d’s might and vengeance was my salvation.” When Moses referred to G’d by the term עזי, he paraphrased what is written in Psalms 68,29: צוך אלו-היך עזך, “your G’d has ordained might for you.” The words זמרת י-ה are related to Samuel II 23,1 ונעים זמירות ישראל, “the favorite of the songs of Israel.” This term also occurs in Psalms, 47,7 זמרו לאלו-הים זמרו, “Sing, O sing to G’d; O sing.”
ויהי לי לישועה, “G’d became my salvation.” The reason the redemption from Egypt is always referred to as ישועה, is because it was followed by another exile. The redemption of the future which will not be followed by another exile, will become known as ישועות, (plural). This is why we have David (Psalms 53,7) express his hope for מי יתן מציון ישועות ישראל, “O that the deliverance of Israel might come from Zion!” On another occasion the final redemption is called תשועת עולמים, in Isaiah 45,17: ישראל נושע בה' תשועת עולמים, “But Israel has won through the Lord triumph everlasting.” In a parallel sense the “song” Moses sang at the Sea of Reeds is known as שירה, “a song (feminine),” whereas the song that will be sung after the final redemption will be known as שיר, “a song (masculine),” reflecting the permanent nature of that redemption; compare Isaiah 26,1 ביום ההוא יושר השיר הזה,”On that day this song which will be sung will be masculine.”

Our sages in the Sifri Haazinu 333 state that some of the greatness of a שירה is that it deals not only with the past and the present but also deals with aspects of the future, the world to come. Tanchuma asks why the שירה which is in the past tense is completely in the feminine gender, whereas the parts referring to the future have been written in the masculine gender? The answer given is that just as a woman who becomes pregnant and gives birth normally repeats the process again and again, so past redemptions and salvations of the Jewish people resulted in renewed exiles. Not so with the redemption of the future which will be absolute, final, not to be followed by any further exiles. This is why the prophet uses the masculine term שיר instead of the feminine term שירה, when he speaks of the future. Compare Isaiah 26,1: ביום ההוא יושר השיר הזה בארץ יהודה, עיר עז לנו ישועה ישית חומות וחל, “on that day, this song shall be sung in the land of Yehudah; “ours is a mighty city; He makes victory our inner and outer wall.” Another verse conveying a similar message is found in Psalms 98,1: שירו לה' שיר חדש כי נפלאות עשה, הושיעה לו ימינו וזרועו קדשו, “Sing to the Lord, a new song, for He has worked wonders; His right hand, His holy arm has won Him victory.”

Your might Because of the following it is called “Your might”: because it performed wonders and mighty deeds among the Philistines. And so it is written above (I Chron 16:8-36): “Give thanks to the Lord,” “Search for the Lord and His might.” Our Sages stated further in Tractate Abodah Zarah 24b (I Sam. 6:12): “And the cows sang.” What song did they recite? They said, (Ps. 98:1) “His right hand and His holy arm have gained Him the victory.”