5748. 'And does he not certainly practise divination in this?' means that the celestial knows, from the Divine that resides within it, things that lie concealed. This is clear from the meaning of 'divining' as knowing things that lie concealed. The reason they are known from the Divine is that the celestial of the spiritual, which 'Joseph' represents, is truth from the Divine, or truth that has the Divine within it, see 5704.