Recalling the Exodus[1]
…למען תזכר את-יום צאתך מארץ מצרים כל ימי חייך
…In order for you to remember the day you left Egypt, all the days of your life[2]
Besides the Festival of Pesach, where we recount the Exodus at the Seder, there is an obligation to recall the Exodus from Egypt every day[3]. We fulfill this by saying the third paragraph of Shema both day and night[4], which mentions the Exodus. Now, the Magen Avraham innovates[5] that reciting Shiras HaYam, the Song at Sea that the Jews sang when the Reed Sea split, fulfills this obligation. Now, at first glance, this seems a little surprising. The Song at Sea was recited after the Exodus from Egypt. Why would reciting it be considered recalling the Exodus? The Torah indeed says[6] to recall the day we left Egypt, and the Sea split a week later[7]. Furthermore, the Midrash says that part of the obligation of recalling the Exodus is to recall the final plague of the death of the first born. If one didn’t say it, they haven’t fulfilled their obligation[8].