Now also let it be according to your words

"Very well. I will do what you said." Here "now" does not mean "at this moment," but is used to draw attention to the important point that follows.

He with whom the cup is found will be my slave

This can be stated in active form. AT: "If I find the cup in one of your sacks, that person will be my slave" (See: rc://en/ta/man/translate/figs-activepassive)