Question: What are Reshimot?
Answer: A Reshimo (informational record) is an impression that remains in the Kli (desire) after the Light that filled it departs. Hence, Reshimot are the Lights contained in the Kelim (desires).
What does “the Light departs from the Kli” mean? It means that it does not illuminate the Kli as before because there is no screen, no contact between the Kli and the Light. Hence, the Light shines only from afar, and it is therefore said that Kli contains a little bit of Light.
Reshimot are similar to reminiscences of my past. The Light fills my will to receive (desire) when I, with the help of the screen, acquire the connection with the Light and we merge together because the screen binds the two opposites with one another. But when there is no screen, the Light is not connected with the Kli. It stays in the Kli and doesn’t depart, yet the Kli cannot feel it or cause it to shine. The Light within it is barely perceived, and we call it a “Reshimo.”
We simply express it by saying that the Light departed and left a Reshimo in its place. Yet in truth, it isn’t the case. The Light remained in place and did not depart, but because we don’t feel it, the Light and the Kli are seemingly disconnected.
From the 2nd part of the Daily Kabbalah Lesson 12/13/10, Talmud Eser Sefirot