Shared ground
Psalm 122:8 shifts from the earlier public calls for Jerusalem’s well-being to a personal pledge. The speaker says his motive is relational: “for my brothers and companions’ sakes.” On that basis he commits himself to speak a message, and the message is a blessing of aimed “within you” (inside the community, not only at its edges). These are explicit claims in the verse.
The verse assumes that spoken words matter for communal life. Saying “peace” is presented as a concrete action, not just an inner attitude. In the psalm’s setting, “peace” naturally includes stable conditions for life together—safety, social harmony, and well-being—rather than only private calm.
Where interpretation differs
Two main questions are left open by the wording.
First, who is “you”? Some read it primarily as the city (Jerusalem as a place). Others read it as the people in the city (the community gathered there). Many see both together, since the psalm treats city and people as closely linked.
Second, what kind of speech is “I will now say”? Some take it as direct speech addressed to fellow worshipers or to the city in a poetic way (“Peace be within you”). Others hear it mainly as prayer-language directed to God on Jerusalem’s behalf, even though the line is phrased as something said to “you.”
Why the disagreement exists
The psalm speaks to Jerusalem in the second person while also describing worshipers and residents within it. Also, Hebrew “say” can cover a range of speaking acts (announcing, greeting, blessing, or praying), and the line doesn’t explicitly identify the immediate audience beyond “you.”
What this passage clearly contributes
This verse contributes a simple theological picture: concern for close relationships (“brothers and companions”) motivates public-facing speech that seeks the community’s wholeness. It also links the psalm’s vision of peace to what happens “within” the community, not only external protection. In the flow of Psalm 122, personal loyalty and communal welfare belong together (compare the next verse’s similar motivation focused on the house of the LORD: Psalm 122:9).