Clue: Man like Esau in Spooner's prayer (4,4)
Answer: HAIL MARY
Explanation: Definition: prayer
A Spoonerism of HAIRY MALE ('man like Esau'). The word order suggests that the tail ends of the words are being exchanged, whereas a Spoonerism generally transposes the initial sounds – and, of course, the clue would read more naturally if HAIRY MALE were the answer.