The word Torah comes from the word hora'ah – teaching. Everything in the Torah contains a teaching for the service of God by every Jew everywhere at all times. Parashat Pekudei is the last parashah in the Book of Exodus. Vayikra is the first parashah in the Book of Vayikra. What can we learn from this? The end of the Pekudei section speaks about the cloud caused by the Divine Presence that covered the Mishkan when its construction was completed. The concept symbolized by the cloud is concealment, as it is written: "Moses could not enter the Tent of Meeting because the cloud was upon it.”.
The Torah continues with the Book of Leviticus and its first section, which gives the book its name. The word Leviticus translates as "He called," where God calls Moses to the Tabernacle to transmit new laws of the Torah. The meaning of a calling is related to revelation, where the one who calls "reveals" himself to the receiver through the call.
It is well known that the revelation following a concealment is much more powerful than the revelation itself. This can be seen with a very simple example: the game of hide-and-seek between a father and his young son. The child enjoys it much more when the father reveals himself after having hidden than when his father is simply standing next to him, already revealed.
Similarly, parashat Vaikrá represents the calling - the revelation - following the concealment of parashat Pekudei - the cloud.
This concept has a practical application in the service of the Jew to his Creator in the concept of Teshuvah – return. Teshuvah is the approach to God – revelation – applicable after one has turned away – hidden – from Him.
In Teshuvah there is also that advantage of approaching after distancing oneself, as our sages say, that there is a high level of Teshuvah where intentional transgressions (which represent the highest level of distancing oneself from God) become merits in favor of the person in the final judgment.
We will understand this idea after examining another phrase from our sages: in the place where the Baalei Teshuvah - the masters of return - stand, the Tzadikim Gmurim - the completely righteous - cannot stand.
In observing the Torah's precepts, there are two movements: positive precepts, which consist of "doing something," and negative precepts, which consist of "not doing something." The Tzaddikim (righteous ones) have no connection whatsoever with evil or anything that opposes the Divine Will; therefore, they have no way of elevating it. Conversely, the Baalei Teshuvah (those who have had a circumstantial connection with evil) can, through repentance (Teshuvah), elevate even those aspects of the world that are initially forbidden by the Torah.
This is the teaching of the parashot Pekudei and Vayikra—concealment and revelation. Whatever situation one finds oneself in regarding the observance of Torah and mitzvot, one cannot give up, God forbid, but must know that by overcoming concealment, one can attain an even higher revelation.
The same applies to generations. One might ask, if previous generations, who were far more pious and observant, could not bring about the Final Redemption, how can we, in our current decadent state, ever achieve it?
The answer lies within the question itself: the deeper the night, the closer one is to the light of dawn. Consequently, as the night progresses, one becomes increasingly sleepy. One must strengthen oneself to avoid falling asleep and to be able to see the light of dawn. Night represents exile. The light of dawn represents redemption. Sleep represents the power of the Yetzer Hara—the evil inclination—which seduces us to abandon the Torah and its mitzvot and "fall asleep" so as not to see the light of dawn.
Extracted from Likutei Sijot vol 1 p. 202