Question: The first Egyptian plague is water turning to blood. What is this blow from the Kabbalistic point of view?
Answer: In the spiritual sense, water symbolizes the quality of bestowal and blood the quality of reception.
For a time, the children of Israel lived in the quality of bestowal, from which they fed, through which they existed united among themselves. But suddenly this quality no longer unites them.
Even the minimal amount and quality of connection that they could achieve disappeared and they felt completely disconnected. They saw that the Pharaoh wanted to rule over them to such an extent that there was no connection left. And so they couldn’t go on like this.
The plague by blood is the first realization of their egoistic intentions, which lead them to absolute death.
From KabTV’s “Spiritual States” 1/30/20