Final answer:
The passage referencing the 'classical pagan past' within the context of the Paris Psalter and a Biblical king in the Byzantine Empire contains the reference to pagan religion.
Step-by-step explanation:
The passage that contains a reference to the pagan religion of the past is: 'The classical past and the medieval Christian present Why would a Biblical king surround himself with pagans? The Paris Psalter embodies a complex mixture of the classical pagan past and the medieval Christian present—all brought together to communicate a political message by the Byzantine emperor.' This passage refers to the blending of pagan and Christian elements during the medieval period, specifically in the context of a Biblical king and the artwork known as the Paris Psalter.