E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
On the introduction of Christianity, the custom of wassailing was not abolished, but it assumed a religious aspect. The monks called the wassail bowl the poculum caritatis (loving cup), a term still retained in the London companies, but in the universities the term Grace Cup is more general. Immediately after grace the silver cup, filled with sack (spiced wine) is passed round. The master and wardens drink welcome to their guests; the cup is then passed round to all the guests. (See GRACE CUP.)
A loving or grace cup should always have two handles, and some have as many as four.
Loving Cup. This ceremony, of drinking from one cup and passing it round, was observed in the Jewish paschal supper, and our Lord refers to the custom in the words, Drink ye all of it.
He [the master of the house] laid hold of the vessel with both hands, lifted it up, and saidBlessed be Thou, O Lord our God, thou king of the world, who hast given us the fruit of the vine; and the whole assembly said Amen. Then drinking first himself from the cup, he passed it round to the rest.Eldad the Pilgrim, chap. ix.