A sample of what appears in the Real Messiah order it hereSeveral of the commentators that I read, such as Rashi and Ramban, point to
other examples of the future being used in the past, such as um. 21:17, Josh
10:12, 1 Kings 7:8 and 1 Kings 11:7. They understand it as meaning that
Moses decided to sing, and then sang. Ibn-Ezra says: "it is customary for
the narrator to put himself in the place of the character - to look at
things from his prospective".
Rashi does quote the Talmud (Sanhedrin 91b) as bringing this as proof of the
future resurrection of the dead, but he takes this to be a secondary
midrash, not the literal meaning of the verse. Hezkuni quotes Ramban (not in
his commentary on Exodus) as understanding "then Moses and the Children of
Israel WILL SING" as meaning that the Song of the Sea is to be sung every
day for all generations - which certainly reflects Jewish practice since
antiquity - the Song is recited as part of the daily prayers.
