The Focus of a Jew's Life
The true vitality of a Jew is reflected not in his material life, but in his spiritual life. 
In this vein, although "[the meaning of] a verse never extends beyond its simple interpretation,"  the verse:  "And they embittered their lives," can also be understood to mean that the hard tasks which the Egyptians made the Jews perform embittered their spiritual life.
This is somewhat difficult to understand.
One can readily comprehend how "harsh labor with mortar and bricks"  can embitter one's material existence, but how can it have such an effect on one's spiritual life.
True, back-breaking labor presents challenge to one's spiritual life, one's study of the Torah and observance of mitzvos. The verse, however, does not speak of challenges, it speaks of the Jews' lives being "embittered."
How is it possible for that material oppression will embitter spiritual life?
This question can be resolved based on the comprehension of a law which applies to a Hebrew servant, a Jew sold into servitude.
It is a forbidden to make such a servant perform avodas perach, "oppressive labor."
The Rambam defines  the latter term a s referring to "work that has no limit, and which is performed without any purpose."
In the gloss to that halachah, the Hagahos Maimoni explain that this definition is derived from the description of the avodas perach which the Jews performed in Egypt.
These concepts - "work that has no limit, and which is performed without any purpose" - make it possible for us to understand how the Egyptians embittered the Jews' spiritual life in Egypt.
When a Jew involves himself in material affairs according to the directives of the Torah, his efforts are limited, and they are purposeful. For the Torah has established a limit to the extent a Jew must involve himself in material affairs. He must do only what is necessary to make a vessel for G-d's blessings. As it is written,  "And G-d will bless you in all that you do."
Man must "do," but his doing merely creates a vessel, the key to success is G-d's blessing.
And then, there will be a limit to the type of energies he invests in earning a livelihood.
This is alluded to in the Chassidic interpretation  of the verse:  "You shall eat the labor of your hands," that our labor should be performed by "our hands ," i.e., the external and lower dimensions of our personalities. Our minds and developed human potentials should be free for other concerns.
Moreover, one's involvement in business concerns should also have a limit in time, so that even a businessman will have enough free time for communal prayer, fixed times for Torah study, and the like.
This will also make a person's activity "purposeful."
For, since his business activity is carried out according to the Torah's directives, it will serve as an appropriate vessel for G-d's blessings.
If, by contrast, a person invest his mental energies in business; i.e., he thinks deeply and seeks crafty plans and cunning devices to make a profit, his efforts will be "work that has no limit, and which is performed without any purpose."
There will be no purpose to these endeavors. They will not bring profit, as reflected by the verse:  "Nor do the wise possess bread." For a person's livelihood is granted to him by G-d. His craft and cunning devices will not bring him anything more; on the contrary, they may detract from him receiving his portion. Nor will such efforts have a limit, for a person who relies on such devices will know no restraints.
Look at him at work. The evening has come; all his workers and hired help are homeward bound. It's time to close the business, but he, the owner, is still preoccupied; he's worrying about his business.
Moreover, even when he finally comes home, instead of setting up a fixed time for study, learning both nigleh and Chassidus, he is still busying running around - either actually running around, or at the very least, his ideas are running around - concerned with his business.
Even when he goes to sleep, "[his] thoughts come to [him] on [his] bed;"  he is still conceiving different plans. And as a result, even when he sleeps, his dreams revolve around what concerns him during the day,  his business.
A similar pattern can even apply with regard to a Torah scholar.
Although his energies are not concentrated on business, they may be centered around his honor and his reputation. If someone makes a remark about him which is not entirely to his liking, he becomes upset. Afterall, he is a Torah scholar, and he must defend the honor of the Torah.
And since "the righteous resemble their Creator," he must follow G-d's ways. Just as G-d rewards man "measure for measure,"  so too, must he make just accounts with the one who belittled him.
Moreover, since the honor of the Torah is involved, he must pay that person back with a double and perhaps even with a manifold measure. This is what concerns him, and this is what he thinks about during the entire day.
At night, when he makes a cheshbon hanefesh, thinking over his spiritual endeavors, this is his focus. And needless to say, afterwards, this effects his dreams as well.
There are material concerns which are purposeful.
For example, when a person thinks about maintaining his physical health, he has a valid reason: "Since maintaining a healthy and sound body is among the paths of G-d,"  he understands that a healthy body is necessary for his Divine service.
This is especially true when a person studies Chassidus and knows the Baal Shem Tov's interpretation  of the verse:  "When you see a donkey... fallen under its load,... you shall surely help unload it." The Baal Shem Tov explains that a donkey (chamor in Hebrew) refers to our material concerns (chomer) and more particularly, to the body.
Our approach should not be to break or to reject the body, but to lift it up. This is especially true with regard to a Jewish body, for a Jewish body is chosen by G-d Himself, as it were. 
Since a Jewish body is so dear, we must care for it. This concern is a material activity with a purpose.
Crafty business deals and the pursuit of honor, by contrast, are worthless pursuits. They are "work that has no limit, and which is performed without any purpose."
Above All Limits And Purpose
On this basis, we can appreciate what the Torah means by saying that the Egyptians embittered the Jews' spiritual life. For the Egyptians endeavored to tap the unique spiritual potential possessed by the Jews and use it for their purposes.
Everything which G-d created in the world was made with a limit, and with a specific intent. What is the source for "work that has no limit, and which is performed without any purpose"?
This refers to a potential possessed only by our G-dly souls.
For the G-dly soul is connected with G-d's essence, a level which is truly unlimited. And because of that connection, the soul is granted unbounded powers, potentials that know no limits.
Moreover, these potentials are also above the sense of purpose.
For example, every Jew possess a potential for mesirus nefesh, self-sacrifice, i.e., devotion that transcends the limits of reason and logic. This reflects a positive concept of "work without a purpose," that one's Divine service is performed without any concern for reward, instead, it is avodah lishmah in the fullest sense. 
There is, however, the possibility of transforming the power of the G-dly soul, and using it for the purposes of evil.
"They consider darkness as light, and light as darkness; they consider the bitter, sweet, and the sweet bitter."  This leads to "back-breaking work," "work that has no limit, and which is performed without any purpose." And this embitters the spiritual life of the G-dly soul.
In Touch With One's Personal Mission
We can appreciate the concept of "And they embittered their lives," on a higher plane, i.e., the person uses his spiritual vitality in the sphere of holiness rather than for worldly matters.
Nevertheless, he uses this vitality for purposes outside the thrust of Divine service destined for him, in a manner which hampers progress on his personal path of Divine service. There is a specific mission for which every soul descends to this world.
When the yetzer hora wants to hinder a person's Divine service, it won't necessarily tell the person to ignore Divine service entirely, for there are those who will not listen to such enticement. So instead, the yetzer hora encourages him to devote himself to Divine service, but urges him to follow a path of Divine service which is not his own, but rather appropriate for another person.
In general, the Jews are divided into two categories:
- Torah scholars, and in particular yeshivah students, whose fundamental thrust is the study of the Torah. They must also perform deeds of kindness (in both a material and a spiritual sense), especially, spreading the wellsprings of Chassidus. This is intrinsically related to their success in Torah study, for our Sages have taught:  "If one says, 'I will be devoted solely to Torah,' he will not even possess the Torah." And thus, a Torah scholar always couples his endeavors with deeds of kindness.  Nevertheless, his primary focus is the study of the Torah.
- Businessmen, whose primary focus is the observance of the mitzvos, and in particular, the mitzvah of tzedakah, which is the paradigm of all mitzvos that involve deed. 
In this way, he spreads forth the wellsprings of Yiddishkeit, Torah, and Chassidus, which is a spiritual expression of tzedakah.
Nevertheless, in the sphere of holiness, all the different attributes are interrelated, and thus businessmen must also have fixed times for the study of the Torah to complement their preeminent efforts in the realm of tzedakah. 
Unfortunately, there are "souls that have lost their way," people who ignore the mission which they have been charged with, and instead involve themselves in matters which are destined for others. There are businessmen from whom it is demanded that they give tzedakah and involve themselves in spreading the wellsprings outward. How do they reply? They explain that they are busy, that can't give their time to anyone else; they must prolong their prayers, and devote themselves to intense study. And directly afterwards, they've got to run to their business. And thus they do not have any time to give tzedakah or to do a favor for another Jew.
In the same vein, there are yeshivah students who dedicate themselves to tzedakah projects, but so much so that they ignore the fixed times established for the study of the Torah.
So confused are these particular souls that they put their main energies into the path of service which is not their own; this is where they invest their vitality and spirit (this lasts, however, only briefly).
Although these are holy endeavors, since this is not the purpose for that soul, involvement in these activities "embitters [one's] life," for it uses the energy of the G-dly soul for objectives outside the scope of its own purpose, and indeed this disturbs the accomplishment of that purpose. 
The Awareness of Freedom
In response to these forces which "embittered [the Jews'] lives," the Jews obeyed to G-d's command:  "Draw out and take sheep... for the Pesach sacrifice."
And it is this which generated the merit for the exodus.
For bringing this sacrifice involved taking the false deity of the Egyptians, a sheep, and slaughtering it before the Egyptian's eyes.
This initiative stemmed from a power that knows no bounds, the power of mesirus nefesh which transcends the limits of reason and logic. Its expression involved redirecting the power of the G-dly soul to its proper place.
And this leads to freedom, and as the Tikkunei Zohar states  this includes "freedom from foolishness." A person gains the genuine knowledge to appreciate what comes from the G-dly soul, what comes from the animal soul, and what comes from even lower sources of influence.
This is the spiritual counterpart of the exodus from Egypt, freeing the powers of the G-dly soul from exile. And this in turn is the catalyst which brings the actual redemption.
(Adapted from Sichos Leil Sheni D'Chag HaPesach, 5719, and 5720)
- (Back to text) See Iggeres HaKodesh, Epistle 27, which states that the life of a tzaddik - and "your nation are all tzaddikim" - is "faith, love and fear of G-d." This applies to all Jews; when a person realizes this potential and live as a tzaddik, his life centers solely on these three attributes.
- (Back to text) Shabbos 63a.
- (Back to text) Shmos 1:14.
- (Back to text) Ibid.
- (Back to text) Mishneh Torah, Hilchos Avodim 1:6.
- (Back to text) Devarim 15:18.
- (Back to text) See the explanation of this concept in Likkutei Sichos, Vol. I, Parshas Vayakhel, and in the sichah to Parshas Vayeitzei in this series.
- (Back to text) Tehillim 128:2.
- (Back to text) Koheles 9:11.
- (Back to text) See Derech Mitzvosecha, p. 107b.
- (Back to text) Daniel 2:29.
- (Back to text) See Berachos 55b.
- (Back to text) Nedarim 32a et al.
- (Back to text) Rambam, Mishneh Torah, Hilchos De'os 4:1. See the discussion of this quote in the notes to the Sichah of Parshas Vayeishev in this series.
- (Back to text) Cited in HaYom Yom, entry Shvat 28.
- (Back to text) Shmos 23:5.
- (Back to text) Tanya, ch. 49. See also Sichas Simchas Torah, 5669 (Toras Sholom, p. 120ff).
- (Back to text) See Rambam, Mishneh Torah, the conclusion of Hilchos Teshuvah; Likkutei Torah, Parshas Re'eh 24d.
- (Back to text) Yeshayahu 5:20.
- (Back to text) Yevamos 109b. See Sefer HaMaamarim 5708, p. 266, note 7. 51. See also the Sichah of Parshas Vayigash in this series. 52. See Tanya, ch. 37.
- (Back to text) See Sichas Chai Elul, 5722.
- (Back to text) See Tosafot, Ketubos 17a, entry mivatlin.
- (Back to text) Shmos 12:21.
- (Back to text) Tikkun 56.