(27) We read the following in Sh’mot Rabbah 23,1 concerning psalms 93,2 where the psalmist describes G’d’s throne as having been firmly established since “אז,” that Rabbi Berechyah, citing Rabbi Avahu says as follows:” what the psalmist has in mind is that You (the Lord) have never sat securely on Your throne, and Your Name has not become a byword amongst mankind until after Your children, the Jewish people, aggrandized Your Name in song and poetry, i.e. with the song commencing with אז ישיר. The sages in the Midrash explain that a king, until he has won impressive victories in battle, may be a king in name only. Once he has won impressive victories he is no longer referred to only as “king,” but as “Emperor.” The Israelites conveyed this idea in the shirah, by recalling that prior to the experience at the sea of reeds, G’d was perceived like a king who is standing upright, measuring the contours of the earth [compare Chabakuk 3,6). Now that He had won impressive victories, He is perceived as sitting on His throne, [resting on His laurels. Ed.] The song that the Israelites sang after the Egyptians had been drowned may be viewed as an accolade to the newly revealed aspect of G’d the Creator.
What precisely was the new aspect of G’d that the people had experienced so that the Torah described it as:וירא ישראל את היד הגדולה....ויאמינו בה' ובמשה עבדו, “Israel saw the great hand of the Lord, etc,….and they had faith in the Lord and in His servant Moses?” After all, they had already witnessed the splitting of the sea, the marching through the sea’s bed as if marching on dry land, the sea’s reversing direction and drowning their enemies.” What new dimension was revealed to them as a result of which they decided to break out in song?
Surely, the word אז, “then,” as well as the word: ישיר in the future mode must contain the answer to our question!