“Consecrate to Me every firstborn; the first issue of any womb among the children of Israel, whether man or animal, is Mine” (Exodus 13:2). “Consecrate to Me every firstborn” – Rabbi Natan says: The Holy One blessed be He said to Moses: ‘Just as I made Jacob the firstborn, as it is stated: “Israel is My firstborn son” (Exodus 4:22), so I will make the messianic king the firstborn, as it is stated: “I also will appoint him firstborn” (Psalms 89:28).
So, “consecrate to Me every firstborn.”12The midrash is explaining that the superfluous word “every” teaches that there is another firstborn who will be consecrated in the future – the messiah. Caution Israel, just as I created the world and I said to Israel to remember the Sabbath day to commemorate the act of Creation, as it is stated: “Remember the Sabbath day,” (Exodus 20:8), so you should remember the miracles that I performed on your behalf in Egypt, and remember the day that you departed from there, as it is stated: “Remember this day that you departed from Egypt” (Exodus 13:3).
Why? “Because with strength of hand the Lord took you from Egypt” (ibid.).13The midrash has “took you from Egypt.” The actual verse is “took you from this.” “No leaven shall be seen with you [in all your borders] for seven days” (Deuteronomy 16:4), corresponding to the seven days between the redemption and the splitting of the Red Sea.
Just as initially there were seven days of Creation and just as Shabbat takes place once every seven days, so shall these seven days be observed each and every year, as it is stated: “You shall observe this ordinance at its appointed time from year to year” (Exodus 13:10). It is analogous to a king who married a woman who was overseas.14The marriage took place remotely, while she was still abroad.
Waves reached her [i.e. she encountered a storm] before she came to him. He said to her: ‘Do not remember all the waves that passed over you, but rather, on that day that you were spared from them, remember me and make a celebration every year.’ So with regard to Israel, the Holy One blessed be He appeared to them to redeem them, and some harsh waves passed over them, but He provided salvation for them.
That is why He cautioned them that they should celebrate every year, as it is stated: “Rejoice in the Lord, and be glad, righteous ones” (Psalms 32:11).