E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Inter Cæsa et Porrecta.
Out of hand. Many things may occur between the cup and lip. (See Cicero: Ad Attcum, v. 18.) Literally, between the slaughter (cæsa) of the sacrificial victim and its being laid (porrecta) on the altar. It was not permitted to speak while the priest struck the animal, nor yet while the sacrifice was being consumed by fire; but between these intervals persons were allowed to talk.