1 Corinthians 10:16

“The cup of blessing, which we bless, etc.] Meaning the cup of wine used in the Lord’s supper, which being set apart for that service, is taken up, and the name of the Lord called upon over it; and he is blessed and praised for his wondrous love and grace, in the gift and mission of his Son, to shed his precious blood for us, for the remission of our sins; the whole church joining with the administrator, both in the act of blessing and praise over the cup, and in the participation of it. This cup is so called in allusion to the cup of wine used at common meals, or at the passover among the Jews, which they used to take and bless God with, and give him thanks for their mercies, and was…”

“The cup of blessing--answering to the Jewish "cup of blessing," over which thanks were offered in the Passover. It was in doing so that Christ instituted this part of the Lord's Supper (Mat 26:27; Luk 22:17, Luk 22:20). we bless--"we," not merely ministers, but also the congregation. The minister "blesses" (that is, consecrates with blessing) the cup, not by any priestly transmitted authority of his own, but as representative of the congregation, who virtually through him bless the cup. The consecration is the corporate act of the whole Church. The act of joint blessing by him and them (not "the cup" itself, which, as also "the bread," in the Greek is in the accusative), and the consequent…”

“The cup of blessing which we bless - The design of this verse and the following verses seems to be, to prove that Christians, by partaking of the Lord’s Supper, are solemnly set apart to the service of the Lord Jesus; that they acknowledge Him as their Lord, and dedicate themselves to him, and that as they could not and ought not to be devoted to idols and to the Lord Jesus at the same time, so they ought not to participate in the feasts in honor of idols, or in the celebrations in which idolaters would be engaged; see 1 Corinthians 10:21. He states, therefore: (1) That Christians are “united” and dedicated to Christ in the communion; 1 Corinthians 10:16-17. (2) That this was true of the…”

“The cup which we bless - By setting it apart to a sacred use, and solemnly invoking the blessing of God upon it. Is it not the communion of the blood of Christ - The means of our partaking of those invaluable benefits, which are the purchase of the blood of Christ. The communion of the body of Christ - The means of our partaking of those benefits which were purchased by the body of Christ - offered for us. 1 Corinthians 10:17”

“10:16-18 Paul affirms the spiritual meaning of sacred meals. In the Lord’s Supper, believers share in the blood and body of Christ (see also 11:17-34; Matt 26:26-28; Mark 14:22-24; Luke 22:19-20). Sharing one loaf unites believers as one body in Christ, just as the pagans’ religious meals unite them with the gods they worship (see 1 Cor 10:19-21).”

“cup: Co1 10:21, Co1 11:23-29; Mat 26:26-28; Mar 14:22-25; Luk 22:19, Luk 22:20 the communion of the blood: Co1 10:20, Co1 1:9, Co1 12:13; Joh 6:53-58; Heb 3:14; Jo1 1:3, Jo1 1:7 The bread: Co1 11:23, Co1 11:24; Act 2:42, Act 2:46, Act 20:7, Act 20:11 1 Corinthians 10:17”