Please realize that I am not a competent halachic authority. Contact one for a practical ruling.This is dedicated to my brother-in-law DD on the occasion of his becoming a בר מצוה, שבת שירה ה׳תשס״ב.
Why is this week called שבת שירה? Certainly, שירת הים is read this week, but do we denote by שבת הדברות the week in which we read יתרו? Or by שבת שמע the week of ואתחנן? Granted, we do call the week in which we read פרשת בראשית by the appellation שבת בראשית, but the question remains.
The שבת before פסח is called שבת הגדול, the great שבת. שו״ע notes that this is
after the miracle that happened then in the year of יציאת מצרים. Another reason often given, though, is that it is named after its הפטרה, which refers to
יום ה׳ הגדול. Similarly, שבת שובה is named after its הפטרה, שובה ישראל, and the same is true for שבת חזון and שבת נחמו. Again, this could apply here — our הפטרה is שירת דבורה — but why choose this week to name? Couldn't we as well call the week of בלק by the name שבת הצנע לכת?
ספר התודעה asks a similar question, and gives a beautiful answer:
Not only שירת הים is in this פרשה; many other ideas are.... Nonetheless, the Jewish people has designated that this שבת be named specifically after the שירה, for this שירה was for Jews throughout the generations as if they were then saying it. Why so? Because whereas ה׳ spoke the entire Torah, and the Jews listened, here the Jews spoke and ה׳ and all His hosts listened....
For with the strength of the שירה that they then sang, they planted שירה and joy in the heart of every Jew, for all time; every time they are saved from their enemies and granted reprieve from their troubles, their hearts sing... to ה׳ Who saved them.
On another note, ספר אהל משה, by Rabbi Moshe Rosen of New York, notes that this week should not, by rights, be called שבת שירה merely because we read the שירה. After all, we read the שירה on a daily basis, so what makes this day special? Further, it can't be called שבת שירה because we commemorate the miracle of the sea now — we do that on the seventh of פסח, the anniversary of the crossing.
He answers that the reason the Jews sang at that point — even though a
trip through the deadly desert was still before them — was that they
trusted that ה׳ would take care of them.
ויאמינו בה׳ ובמשה עבדו, אז ישיר.... So we refer only to this day as שבת שירה, as this is the only day on which we also read all the troubles that they went through in the desert. (Every day, when we read the שירה, we read it alone, without recalling the hardships of the desert.) When we read it this week, it strengthens our own בטחון. (We do not call the seventh of פסח by the name יום שירה because we do not need to strengthen our בטחון, as we are שרויִם and have בטחון.)
It is customary to feed birds grains of wheat (מג״א) or of kasha (מאיר נתיב, אוצר דינים ומנהגים), or leftover שבת dishes (שש״כ), on שבת שירה. Several reasons are given for this:
However, it is, in fact, forbidden to feed an animal on שבת, unless that animal is dependent for food upon the one feeding it. For this reason, מג״א writes that the custom of feeding stray birds on שבת שירה is improper. עה״ש justifies the custom, writing that we do not feed the birds for their own sake, but, rather, for ours, as we wish to remember the joy of the crossing of the sea (note his reason, above, for the custom). Indeed, the entire reason we may not feed stray animals on שבת is that it is too much labor (טירחא) for us; if we do it for our own sake, not the animals', or, especially, if we do it in fulfillment of a custom, then there is no problem. So goes the argument. Nonetheless, שו״ע הרב, קש״ע, and מ״ב — a formidable list of latter-day פוסקים — all write, as מג״א does, that the practice is forbidden, and שש״כ accepts this as הלכה. However, שש״כ quotes אשל אברהם as writing that since the reason for the prohibition is merely טירחא, it is permissible to allow one's children to feed animals, and it is appropriate to do so on שבת שירה. Further, if one is going to shake off his tablecloth anyway, then there is no greater טירחא in doing so out of doors (where there is an עֵרוב), in the direction of birds. Finally, אשל אברהם also writes the obvious היתר that one can feed pet birds, if he has any — birds that are dependent on him for sustenance.
ב״ח mentions the custom of eating cooked, whole wheat kernels on שבת שירה, noting also that whole barley was eaten the rest of the year. It is customary in many אשכנזי circles to eat whole barley in chulent on שבת, although I have not heard of anyone who substitutes wheat for barley on שבת שירה nowadays; I do not know why not. A reason for the custom of eating wheat this week, when we read about the מן, is that the מן was like wheat kernels. A hint to this custom may be found in the name of the פרשה, בשלח, which can be viewed as an acronym for
לאכול חטים בשבת שירה,
eat wheat on שבת שירה (לקוטי מהרי״ח).
There is a חב״ד-Lubavitch custom of eating kasha on שבת שירה.