Ps 22:30 is quintessential Hebrew poetry being frustratingly terse - the Hebrew contains only five words! For what it is worth, here is my translation:
[A] posterity/seed shall serve Him; it will be recounted of the Lord
to [the] generation/age
Before interpreting this verse, let me observe several things:
- posterity/seed is singular
- "Him" is the only pronoun in the verse
- "it" is implied by the 3rd person masculine singular verb
The central question here is (as per the OP's question), who/what is the posterity/seed, Heb: זֶ֥רַע (zera)? There are two options:
- posterity/seed refers to a group/nation/class of people - if this is true, it refers to God's people serving God
- posterity/seed refers to a single person - if this is true it is almost certainly Messianic.
Now, good arguments can be made for both options. However, the solution almost certainly lies in observing the parallelism of the final stanza - the last three verses. Here is my translation of the final stanza:
V29: They shall eat and worship all the prosperous/strong of earth
before Him shall bow
all those who go down to dust
and even Himself who cannot keep alive
V30: [A] posterity seed shall serve Him
it will be recounted of the Lord to [the] generation/age
V31: They will come and declare His righteousness to a people
That He has done
This appears to be simply saying that either:
- a future people will worship and serve God and declare His righteous attributes, even the resurrected dead who have gone done into the dust (a euphemism for the grave), OR
- a future Messiah will serve God and this will bring praise and service to God.
Most commentaries settle on the first version, but I cannot completely dismiss the second option. One of the reasons for this is Paul's statement about the "seed" -
Gal 3:16 - Now the promises were spoken to Abraham and to his seed. It
does not say "and to seeds" as of many but "and to your seed" as of
One, who is Christ.
There are two more things that suggest (to me) that this part of the psalm is Messianic:
- Jesus' comment in John 12;32 that, "And I, when I am lifted up from the earth, will draw everyone to Myself.”
- In Ps 22:29 says, "and even Himself who cannot keep alive" almost certainly refers to Jesus especially when He prayed in the garden to be excused from the coming trial and execution, but then also prayed, "Your [the Father's] will be done". That is, Jesus had life in Himself (John 1:4, 5:26) and raised Himself from the dead (John 2:19, 10:17, 18) but voluntarily submitted to the Father and His execution (Phil 2:5-8).