Sefer Chasidim

When you see a person prophesying about the Messiah, you should know that he is either engaged in witchcraft, or has dealings with demons, or has adjured them with the Ineffable Name. Because such a sorcerer importunes the angels or the spirits, they say to him: 'Speak not in this manner, rather reveal the coming of the Messiah to the whole world.' But at the end he will be put to shame before the whole world, because he importuned the angels or the demons. And in its place misfortunes come because of him who adjured. And demons come and teach him calculations and secrets, to his shame and the shame of those who believe his words ... for no man knows about the coming of the Messiah.⁠a