The Lord’s supper has historically been called the Eucharist, which means thanksgiving. This name is appropriate not just because the celebration of the supper properly involves prayers of thanksgiving (Luke 22:19, Matt. 26:27), but also because the supper is linked with the Passover feast, which in turn closely follows the form of the peace offering for thanksgiving (Lev. 7).
When the Old Testament refers to thanksgiving, this thanksgiving sacrifice is often in view. Thus, when God’s people enter his gates with thanksgiving (e.g., Ps. 95:2, 100:4), it is not just words of thanksgiving they carry, but a thanksgiving feast that they have come to celebrate. King David appointed a Levitical choir-orchestra (1 Chron. 15), whose performance before God was connected to the offerings and sacrifices (e.g., 2 Chron. 29). Giving praise to God in song is always linked with celebrating thanksgiving to him at his table.
We see this further in the book of Hebrews, where the language of “sacrifice of praise to God” (Heb. 13:15) exactly parallels the language of the Septuagint, which refers to a “sacrifice of praise” (Lev. 7:12 LXX) rather than a “thanksgiving sacrifice.” Similarly, Hebrews’ use of “continually” (also Heb. 13:15) repeats the expression used by the Septuagint to refer to the daily tribute offering (Lev. 6:20 LXX), which we have also linked to the Lord’s supper.
Thus, weekly Eucharist: because to enter God’s courts with praise is precisely to enter his gates with a thanksgiving feast; and because the fruit of our praise-giving lips is to celebrate a sacrifice of praise, that is, a thanksgiving feast.
Thanks to Peter Leithart for these reflections.