Seder Symbols - What Do They Symbolize?

This is the bread of destitution that our ancestors ate in the land of Egypt. Anyone who is famished should come and eat, anyone who is in need should come and partake of the Pesach sacrifice. Now we are here, next year we will be in the land of Israel; this year we are slaves, next year we will be free people.

This matsa that we are eating, for the sake of what [is it]? For the sake [to commemorate] that our ancestors' dough was not yet able to rise, before the King of the kings of kings, the Holy One, blessed be He, revealed [Himself] to them and redeemed them, as it is stated (Exodus 12:39); "And they baked the dough which they brought out of Egypt into matsa cakes, since it did not rise; because they were expelled from Egypt, and could not tarry, neither had they made for themselves provisions."

The mishna states: Rabbi Elazar, son of Rabbi Tzadok, says that eating ḥaroset is a mitzva. The Gemara asks: What is the nature of this mitzva? The Gemara answers: Rabbi Levi says: It is in remembrance of the apple, as apple is one of the ingredients in ḥaroset. The verse states: “Who is this who comes up from the wilderness, reclining upon her beloved? Under the apple tree I awakened you” (Song of Songs 8:5), which is an allusion to the Jewish people leaving Egypt. And Rabbi Yoḥanan says: The ḥaroset is in remembrance of the mortar used by the Jews for their slave labor in Egypt. Abaye said: Therefore, to fulfill both opinions, one must prepare it tart and one must prepare it thick. One must prepare it tart in remembrance of the apple, and one must prepare it thick in remembrance of the mortar. It was taught in a baraita in accordance with the opinion of Rabbi Yoḥanan: The spices used in the ḥaroset are in remembrance of the hay that our forefathers used for building in Egypt, and the ḥaroset itself is in remembrance of the mortar. Rabbi Elazar, son of Rabbi Tzadok, said: When selling ḥaroset, the small shopkeepers in Jerusalem would say as follows: Come and take spices for yourselves for the mitzva.

(1) Karpas: One dips vegetables in salt water to symbolize that like karpas, we must undergo an entire immersion of one's entire body -- a complete purification, and not like one who immerses himself with an impure reptile in his hand, God forbid! This is an allusion to the fact that the Israelites were idolaters while they were in Egypt. When God took them out of Egypt to sanctify them by giving them the Torah, they first had to remove the impurity from themselves and to make a complete repentance. And from this rationale, one dips the vegetable to symbolize that a Baal Teshuvah (repentant) must be as humble like the plants in the field which are trampled underfoot.
Therefore it is called karpas, i.e., like refes, which is an expression of being trampled over. Alternatively, it is related to the word refes, spelled with a sin instead of a samech, which is the word for mud or earth. (See Rashi on Prov. 6.) In this way also, it is a reminder that the Israelites were humiliated by the Egyptians; they were like "mud and dirt."
The combination of the words ur'hatz and karpas also hints at the process of purification: first washing and immersing, and then "sprinkling," as we find in the law of the red heifer: the sprinkling to purify was done with a bunch of hyssop. (See Nu.19:18.) Likewise here, we dip a bunch of vegetables as an allusion to this sprinkling. Similarly, He commanded in Egypt to sprinkle blood on the lintel and the doorposts, as it says, "You shall take a bunch of hyssop ..." (Ex. 12:22.)
And the reason for the dipping is that we thereby symbolize that, after you have adorned yourself such that is is appropriate for you to go in for an "audience," to appear before the King, one should show that one is his servant and has acted in accordance with his will and his commands. Thus, one initially dips the greens in salt water or vinegar, to show that there remains in our memories the time when we were humbled while in Egypt and that we left there, and that, in but a little while, we have reached this exalted level.
It alludes to two opposing ideas, subjugation and freedom. First, "they embittered our lives" with subjugation like vinegar or salt water, but ultimately, through the merit of the dipping of the vegetable, that we fulfilled the commandment of sprinkling the blood on the lintel, etc., and all of Israel was saved from the plague of the first born and afterwards we went forth to freedom.

KARPAS. The MaHaRI"L wrote that our practice is to take karpas, which stands for Samech [=60] parech, in other words, 60 myriads performed work of rigor.

This marror [bitter greens] that we are eating, for the sake of what [is it]? For the sake [to commemorate] that the Egyptians embittered the lives of our ancestors in Egypt, as it is stated (Exodus 1:14); "And they made their lives bitter with hard service, in mortar and in brick, and in all manner of service in the field; in all their service, wherein they made them serve with rigor."

Ravina found Rav Aḥa, son of Rava, searching for merirata to use as bitter herbs. He said to him: What is your opinion, that you seek this particular herb? If you are looking for that which is most bitter, but we learned ḥazeret first in the mishna, which indicates that this is the preferred choice. And likewise, a Sage of the school of Shmuel taught ḥazeret first, before the other types of bitter herbs. And Rabbi Oshaya said: The optimal fulfillment of the mitzva is with ḥazeret, and Rava said: What is ḥazeret? It is lettuce [ḥassa]. The Gemara explains: What is the meaning of lettuce [ḥassa]? It refers to the fact that God has mercy [ḥas] on us. And Rabbi Samuel bar Naḥmani said that Rabbi Yoḥanan said: Why are the Egyptians likened to bitter herbs in the verse: “And they embittered their lives” (Exodus 1:14)? This comparison serves to tell you that just as these bitter herbs are soft at first and harsh in the end, so too, the Egyptians were soft at first, when they paid the Jews for their work, but were harsh in the end, as they enslaved them. This idea applies solely to ḥazeret, which has a bitter aftertaste, but not to other types of bitter herbs, which are bitter from the beginning. Rav Aḥa, son of Rava, said to Ravina: I retract my position and concede that it is preferable to use ḥazeret for bitter herbs.

(11) It's a mitzvah to seek red wine (if the white wine is not better) [Tur].

As it is written (Prov. 23:31), "Do not ogle the red wine," [which would be meaningless] were it not for the fact that the redness is an advantage and a quality of importance. And also, as a reminder of the blood, for Par'oh slaughtered the Israelites. And in a place where the Gentiles are accustomed to raising the [blood] libel, [Jews] refrain from using red wine.