Joel 2:17 Let the priests, those who serve the LORD, weep from the vestibule all the way back to the altar. Let them say, “Have pity, O LORD, on your people; please do not turn over your inheritance to be mocked, to become a proverb among the nations. Why should it be said among the peoples, “Where is their God?”
The priests from one end of the temple to the other will plead with the LORD to spare the people of Judah during a time of distress. This is just a way of emphasizing the strong weeping in the temple. The date of Joel is unclear because there is no reference to which king is reigning as there usually is in the prophetic books. However it is likely that the time of distress was the invasion by the Babylonian army in the 6th century BC or earlier by the Assyrian army. Whether or not either of those possibilities is correct the book of Joel also prophesies of a time still future in Israel’s history. Since the temple sanctuary has not been operating for nearly two thousand years, then this verse seems to not have a latter time application, unless of course a temple will be rebuilt in Jerusalem before Christ’s return.