Genesis 44:15 - Can Joseph Certianly Divine?

And Joseph said unto them, What deed is this that ye have done? wot ye not that such a man as I can certainly divine?

Like Daniel, Joseph was appointed Chief Diviner; for he was found to have the Spirit of God (Daniel 4:9, 5:11; Genesis 41:38), not because he could find things out with a cup. Joseph gives the impression he used the cup found in Benjamin's sack as a cup of divination (Genesis 44:5) to enhance the cups value and, more importantly, to prompt the question: wot ye not that such a man as I can certainly divine? If they couldn't believe Joseph's dreams, then how could they believe an Egyptian could use a cup to tell the future?