fence the tables

verb1

1. •
   (Scotland, historical) To make a solemn address to those who present themselves to commune at the Lord's Supper, on the feelings appropriate to the service, in order to hinder, so far as possible, those who are unworthy from approaching the table.

   • January 19 1840, Robert Murray M'Cheyne, Memoirs Felt great help in fencing the tables