Is not this it in which my lord drinketh, and whereby indeed he divineth? ye have done evil in so doing.
This is Joseph's household servant talking. He is talking to other servants who stole the silver cup that Joseph used to both drink from and to DIVINE the future. That last part of "Ye have done evil in so doing", is not against Joseph using divination. It is against the thieves who stole the chalice.
You can divine exactly like Joseph did. It's not witchcraft. It's right there in the bible and nobody accused Joseph of being a witch. If it's good for the goose, it's good for the gander. There is no way anybody can argue that only Joseph can do this and get away with it.
Fellow and would-be workers, stop listening to the Fundamentalist Christians. Most of them don't even read the bible and have no clue what exactly is contained in it.