E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Come to the last clause. In the long Latin grace at St. Johns College, Cambridge, the last clause used to be Tu autem miserere mei, Domine. Amen. It was not unusual, when a scholar read slowly, for the senior Fellow to whisper Tu autemi.e. Skip all the rest and give us only the last sentence.