In Hebrew, "nature" means "to drown." Nature alone drowns in itself, like the Egyptians drowned in the Red Sea. Faith saves nature's life.
"Havayah is our God Havayah is one." These 4 words correspond to the 4 letters of Havayah, "one" corresponds to the final hei, kingdom.
To drown in yourself is to be totally preoccupied with yourself. And so if nature is totally preoccupied with itself, it drowns in itself.
What does it mean to regret one's sins? It's like a person drowning, he regrets having gone that day to the sea.