We were slaves to Pharaoh in Egypt

From Rav Joseph B. Soloveitchik, "An Exalted Evening".
עבדים היינו לפרעה במצרים
Avadim hainu l'phar'oh b'mizrayim
We were slaves to Pharaoh in Egypt

We were slaves to Pharaoh, not Pharaoh's slaves.  The former would be only a juridic-social description; the Jews belonged to Pharaoh legally, but spiritually we were free people with our own individual minds and an independent approach to reality. However, when we state that someone is "Pharaoh's slave," we identify his whole personality with Pharaoh. Serving Pharaoh is not just incidental; it is the whold purpose of his life.  Pharaoh's Egyptian slaves are called "avdei Phar'oh".  Our service to the Almighty is not something foreign and incidental, but rather something indispensable to our existence, something intrinsic and inseparable from our ontological awareness. That is why the term "eved Hashem, G-d's servant" is used in the Bible. We are only servants of G-d, and nothing else.

Moses had doubts about the Jew's eligibility for freedom. He thought of them as slaves, especially after his very unpleasant experience with the two Hebrew slaves who were fighting. Moses was in despair, wondering whether the Jews were worthy of redemption. Therefore, G-d presented him with the very strange revelation of the burning bush. In its middle was a fire, while its outside was cold and dark. From the outside, it looked just like any other thorn bush in the desert; but inside that bush, in its hidden center, there was a fire burning. The ecstasy of the Jews for G-d, their commitment to His path, had never been extinguished in Egypt. It was rather invisible, covered up. G-d told Moses, "Ra'oh ra'iti, I have surely seen the wretchedness of My people who are in Egypt" (Ex. 3:7)

Our Sages say, "Atah ro'eh re'iyah ahat" - meaning, you see only My people in Egypt - "va-Ani ro'eh shetei re'iyot" - whereas I penetrate into the depths (Ex. Rabbah 3).  And once we penetrate into the depth of a Jew, no matter how repugnant his exterior, no matter how subservient he is to the taskmaster, we will find him questing for freedom and searching for G-d. Within every Jew, there is a burning bush. The Jew himself has never become Pharaoh's slave, but only a slave to Pharaoh. "We were slaves to Pharaoh in Egypt", but we remained free, even during the time of oppression.

The Haggadah emphasized: We were slaves not only to Pharaoh, but "to Pharaoh in Egype". Egypt was a corporate state, whose head was Pharaoh. The Pharaoh was not an individual; indeed we do not know his individual name. Even the personality of the king was erased! In a slave society, individuality submerges into a common pool, the faceless crowd of slaves.  This is the meaning of the phrase "Avadim hayinu le-Phar'oh be-Mizrayim. We were his faceless slaves, and the relationship was impersonal. And, of course, an impersonal relationship is a cruel relationship.