Luke 22:17 - Albert Barnes' Notes on the Bible

And he took the cup and gave thanks - This was not the “sacramental” cup, for that was taken “after” supper, Luke 22:20. This was one of the cups which were usually taken during the celebration of the Passover, and pertained to that observance. “After” he had kept this in the usual manner, he instituted the supper which bears his name, using the bread and wine which had been prepared for the Passover, and thus ingrafted the Lord’s Supper on the Passover, or superseded the Passover by another ordinance, which was intended to be perpetual.