The medieval commentator, Rashi, explains that when Moses saw the Red Sea split, and the Jewish nation saved while the Egyptian army drowned, he made the decision that he would sing a song of gratitude, the first-ever song recorded in Jewish history.
Rabbi Avraham Bornstein of Sochatchov, in his Shem Mishmuel commentary, is puzzled by the need for the Torah to say that Moshe made the decision that he ‘would’ do something — it is obvious no one does anything without first deciding to do it. It could therefore quite easily have said: “Az Shar Moshe” – “then Moshe sang”, as opposed to “Yashir”.
Rabbi Dunner uses the Shem Mishmuel to explore the concept of prophecy, touching upon the miraculous nature of Moses’ prophetic powers, and how on this occasion those powers extended to the entire nation. Rabbi Dunner also shares some wonderful lessons we can draw from this seemingly meaningless word differential, lessons we can take on in our day-to-day lives.