Kabbalah zu Bamidbar 21:17

When Israel returned in teshuvah then they sang a song. And those are the seven levels that they returned with their song, and the higher well was raised high, and the snake disappeared from the world. This is what is written "Then Israel sang" (Numbers 21:17) "raise well, answer to it", and the lower mother [malchut, our reality] is infused with the higher mother [binah, understanding]