10:21

the cup of Jehovah: Five verses earlier, Paul speaks about the cup of wine symbolizing Christ’s blood at the Lord’s Evening Meal. (1Co 10:16) There he calls the cup used at this observance “the cup of blessing that we bless.” When Jesus instituted this observance, he said a blessing, or prayer, before passing the cup to his disciples. (Mt 26:27, 28; Lu 22:19, 20) Following this pattern, a blessing, or prayer, is said before drinking from the cup. However, it was Jehovah who made all provisions for Christians, including Jesus’ ransom sacrifice; it was to Jehovah that Jesus offered the merit of his sacrifice; it was the will of Jehovah that governed how that sacrifice would be used; and it was Jehovah who foretold and instituted the new covenant. (Jer 31:31-34) So it is proper to speak of “the cup of Jehovah.”​—See App. C3 introduction; 1Co 10:21a.

the cup of demons . . . the table of demons: Just as the Lord’s Evening Meal is a communion meal​—in certain respects similar to the communion sacrifices in ancient Israel (Le 3:1-16; 7:28-36; 1Co 10:16)​—so sharing in sacrificial meals of idol worshippers would make Christians partakers together with demons. A Christian could not share in the Lord’s Evening Meal and also in the meals of pagans worshipping false gods.

the table of Jehovah: This expression is understood to be a quote from or an allusion to Mal 1:7, 12, where the altar in Jehovah’s temple is called “the table of Jehovah.” It is called a “table” because the sacrifices offered on it are compared to “food [lit., “bread”].” (Mal 1:7; ftn.; Eze 41:22) When the Israelites ate part of the communion sacrifices to God, they became sharers with him, as if partaking of a meal together, for God was represented by the altar.​—See study note on the cup of Jehovah in this verse and App. C3 introduction; 1Co 10:21b.