Shared ground
Psalm 129:8 closes the psalm’s picture of the enemy’s collapse by describing what does not happen in public: passersby do not speak the ordinary words of goodwill that would normally be heard around harvest time. The verse even quotes the missing lines—“The blessing of be on you” and “We bless you in Yahweh’s name”—to underline that the absence is deliberate and noticeable.
The most explicit claim is social: the people referred to as “them” receive no public recognition, no shared joy, and no respectful greeting. The withheld blessing functions as a final sign that their cause has ended in shame, not celebration.
Where interpretation differs
Two main questions get answered differently.
First, who “them” refers to depends on how the earlier images are read. Some take “them” as the psalm’s oppressors (the enemies of Israel). Others emphasize the rooftop-grass image and see “them” as the “crop” itself in the picture—grass that dries up and so never becomes part of any real harvest scene.
Second, the two quoted lines may be understood as a brief back-and-forth greeting (one party speaks, the other answers), or as two parallel ways of saying the same withheld goodwill. The verse itself does not spell out the interaction.
Why the disagreement exists
The psalm moves quickly from metaphor (rooftop grass) to a human “harvest-field” exchange. Because the poem does not pause to explain the shift, readers differ on how tightly the greeting scene should be tied to the metaphor versus the real-world fate of the oppressors. Also, the verse quotes two lines without stating who would say each line.
What this passage clearly contributes
This verse contributes a concrete social marker of downfall: when a person or group is truly “finished,” they may lose not only power but also basic public goodwill. The text’s emphasis is not on a private feeling but on the absence of openly spoken blessing by those who “go by,” completing the psalm’s contrast between Israel’s endurance and the enemies’ withering end.