ben trovato says:
The minister was preaching on the evils of drink.
First he said how he would like to gather up all the wine and dump it in the river.
Then he moved on to beer and said he would like to get all the beer and dump it in the river too; and then all other forms of alcohol to be dumped into the river.
Behind him the choir-master's face began to show a worried look as they all stood up to sing the first hymn: "Shall We Gather At The River?"