מַה נִּשְׁתַּנָּה WHAT MAKES

THIS NIGHT UNLIKE ALL OTHER NIGHTS,
so that every other night we eat either bread or matza,
but tonight there is only matza?

And that every other night we eat many different greens,
but tonight we will eat bitter herbs?

And that every other night we do not dip [our food] at all,
but tonight we will dip it twice?

And that every other night some sit to eat and some recline,
but tonight we are all reclining?

...“Our Sages said that three names were given to it: maror, ḥasa, and ḥazeret.It is called maror (‘bitter herb’) because the Egyptians embittered the lives of our ancestors. It is also because the herb is at first sweet but its end is bitter like wormwood; so too the land of Egypt was sweet for Israel in the days of Joseph, but afterward it became bitter for them.It is called ḥasa because the Holy One, blessed be He, had compassion (ḥas) upon them, as it is said: ‘He turned toward them in mercy and showed them favor.’And it is called ḥazeret because the Israelites were going back (ḥozrim) from door to door.

THESE BITTER HERBS
that we eat:
what do they recall?

They recall the bitterness that the Egyptians imposed
on the lives of our ancestors in Egypt,
as it is said:

“They embittered their lives with hard labor,
with clay and with bricks
and with all field labors, with all the work
with which they enslaved them – hard labor.”

(23) They came to Marah, but they could not drink the water of Marah because it was bitter; that is why it was named Marah.

(24) And the people grumbled against Moses, saying, “What shall we drink?” (25) So he cried out to GOD, and GOD showed him a piece of wood; he threw it into the water and the water became sweet.
There a fixed rule was made for them; there they were put to the test:

One of the ways we encourage such humility is by eating maror, bitter herbs. The word maror has the same numerical value as mavet, death; it is 446. When eating the maror, we should tremble even if we are fortunate enough to have wealth or honor in our lives. No matter what we have, we should contemplate the day of one's death and not be haughty. Rather we should devote ourselves to study, commandments and good deeds. We should remember that God lifts us up from the dung heap and makes us royalty. If one becomes haughty, one should become humble like this bitter herb which is lowly and is entirely bitter.
When chewing the bitter herbs it begins tasting soft and sweet but it becomes bitter the longer we chew on it, as the Talmud explained in Pesahim 39a: “Why is Egypt compared to bitter herbs? Maror starts off soft and it becomes harsher. So, too, life in Egypt started off soft and it became a harsh place for the Israelites in the end.

(20) “Do not call me Naomi,” she replied. “Call me Mara, for Shaddai has made my lot very bitter.

R. Shimon b. Gamliel says: Come and see how different are the ways of the Holy One Blessed be He from the ways of flesh and blood. (A man of) flesh and blood heals bitter with sweet, but the Holy One Blessed be He heals bitter with bitter.