Michael Laitman, On Quora: “What is part of the time between Passover and Shavuot thought to be?“
“And by the exodus from Egypt they received the level of faith…and after Passover, the purifying work begins in preparation for the receiving of the Torah. And when the Torah is dressed in a person’s soul, this is the time of Shavuot, the time of the giving of our Torah.” (Kabbalist Baruch Shalom HaLevi Ashlag [Rabash], “Letter 52”)
Passover marks the end of the time of slavery in Egypt.
Our slavery in Egypt means that we feel problems stemming from the ego to make us want to disconnect from it and elevate ourselves upon it, and identify with the quality of love and giving.
In the process, we renew our efforts to rise above the ego time after time with the help of a supportive environment, i.e., others who share a similar desire to be above the ego and who support each other to do so.
The effort to rise above the ego is the work in Egypt. After we realize the full extent of that work, we receive a positive response to the effort: a force that emerges and corrects us.
That state is called Passover.
It is a significant correction on our spiritual path.
Passover, however, is only one stage toward our full correction. It marks the elevation above our ego.
Afterward, the time between Passover and Shavuot, designated by a count of 49 days, marks a time of disconnecting ourselves from our ego and rising to a level called “Bina,” a state of absolute giving, where there is no egoistic involvement whatsoever.
Shavuot marks the next correction, the full extent of the force we receive from Bina that lets us connect our ego with the force of correction, the force of the Torah. That is, at Shavuot, we don’t merely rise above the ego, as we do in Passover. At Shavuot, we gain the ability to connect our ego with the force of the Torah, which lets us use our ego in a corrected way.
Of course, such an explanation of the time between Passover and Shavuot relates only to the spiritual meaning of the holidays, as described by the wisdom of Kabbalah, which explains that the holidays are states on our spiritual path that we can feel at any moment we apply the necessary efforts to enter such states. See the links in my Quora bio for more info about how to get started with Kabbalah study.