Possible Clues:

• It's mixed with cement for a long passage
• Long written effusion
• Tiresomely long document about creeds
• Lengthy piece of writing
• A tiresomely long letter
• Thin layer of mortar
• There's a long list of things the South may believe
• At length it is written that I believe the beginning at the end
• Tract presenting the Apostle's core convictions
• Singular articles in long letter ...