{The cup of blessing} (	o pot(8872)ion t(8873) eulogias). The cup
over which we pronounce a blessing as by Christ at the
institution of the ordinance. {A communion of the blood of
Christ} (koin(936e)ia tou haimatos tou Christou). Literally, a
participation in (objective genitive) the blood of Christ. The
word koin(936e)ia is an old one from koin(936e)os, partner, and so
here and  Php 2:1  3:10 . It can mean also fellowship ( Ga 2:9 )
or contribution ( 2Co 8:4  Php 1:5 ). It is, of course, a
spiritual participation in the blood of Christ which is
symbolized by the cup. Same meaning for koin(936e)ia in reference
to "the body of Christ." {The bread which we break} (	on arton
hon kl(936d)en). The loaf. Inverse attraction of the antecedent
(arton) to the case (accusative) of the relative (hon)
according to classic idiom (Robertson, _Grammar_, p. 488).
Artos probably from ar(935c), to join or fit (flour mixed with
water and baked). The mention of the cup here before the bread
does not mean that this order was observed for see the regular
order of bread and then cup in  11:24-27 .