זוהר בראשית — דף רמה ע”א

The Community of Israel says: Set me as a seal upon your heart, for like a seal that leaves its imprint even after being removed, so I remain attached to you even in exile. The love from above is as strong as death, and when the assembly below is aroused, the Holy One blessed be He will unite with her in the future. Exile is called fire because she is a burning fire in her love for the Holy One blessed be He. This secret of the bond teaches that the bond of love between the Creator and the Community of Israel is eternal and never changes.