And when Israel went out of Egypt, He killed many of them,lxviiiSee Shemot Rabbah 14:3 and in the final exile, the blessed Holy One is destined, to kill them, and this is: (Ex. 7:18) And the fish (dagah) that was in the river died, and the river (ye-aur) became putrid... – this is the Torah (auraiyta), of which it is stated: (Prov. 6:23)... and Torah is light (aur)... – which became putrid for them.
And it is stated of Israel: (Ex. 1:22)... every son born you shall throw to the river (ye-aur)... Light (aur) is the numeric equivalent of ‘mystery’ (raz, =207), ‘to the river’ (ha-ye-aurah) is the female partner, of that light of which it is stated: (Ex. 10:23)... and for all the Children of Israel, ‘there was light’ (hayah) aur in their habitation.