"O mysterious priest..."See in text(Ode on a Grecian Urn)
The "mysterious priest" would most likely be the priest of Hera, queen of the gods, or Hymen, god of marriages. In ancient Greece, both of these gods traditionally presided over weddings, requiring that a heifer (or cow) be sacrificed in order to bless the marriage.
"Cold Pastoral..."See in text(Ode on a Grecian Urn)
Broadly speaking, the "pastoral" refers to the ideal state of nature. Its roots are Latin, pastoralis meaning the tending of livestock. In poetry, the pastoral is a type of poetry that glorifies the natural world. The urn is characterized as a "Cold Pastoral" because its scenes move from the ideal to the realistic, incorporating images of sacrifice and suffering.
