He goes to the stonemason and asks for a tombstone that says “rest in peace.” A couple of days before the funeral, he comes to check on the stone and sees that it says “Rest in Piece.”
“Sorry,” he says to the mason, “but I meant ‘peace’, with an ‘a’.”
On the eve of the funeral, the mason shows the widower the corrected version of the stone. “I’ve done it with the ‘a’,” he says.