Hisgalus 17:5, 7

And on her metsakh (forehead) a name had been written: SOD BAVEL HAGEDOLAH EM L'ZONOT V'SHIKKUTZEI HA'ARETZ (“Mystery of Babylon the Great, the Mother of Prostitutes and of the Abominations and Idols of the Earth”).

And the malach (angel), said to me, “Why did you marvel? I will tell you the Sod HaIsha (the mystery, raz of the woman) and of the Chayyah (Anti-Moshiach) having the sheva heads and the eser (ten) horns carrying her.