But if that servant says in his heart, My master is late in coming, and begins to strike the other servants ... The master of that servant will come on a day when he does not expect him and at an hour of which he does not know, and will punish him and cut him off and assign his lot with the unfaithful. - Luke 12: 45-46
‘Tanning the Old Lady’s Hide’
On Saturday, September 18, 1937 following his morning discourse, Rutherford released the tan-colored book Enemies. It denounced Christians as “a great enemy, always working injury to mankind.” Christians were identified as “agents of the Devil, whether they are aware of that fact or not.” When presenting the book to the audience, Rutherford said: “You will notice that its cover is tan, and we will tan the old lady’s hide with it.”
To this the audience gave loud and enthusiastic approval.
From merriam-webster: