Here the psalmist is thinking particularly of Yahweh’s blessings on Jerusalem and its people. Verse 12 consists of two parallel and synonymous lines; Zion in line b is used synonymously with Jerusalem in line a.

Yahweh keeps Jerusalem safe and strong and blesses its people. Verse 13a talks about the physical security of the city against outside attacks. Good News Translation‘s “He keeps your gates strong” is the use of a part for the whole, meaning “He defends Jerusalem” or “He guards Jerusalem.” In verse 13b your sons are the citizens of the city (Good News Translation, New International Version, Die Bibel im heutigen Deutsch “your people”).

In verse 14 your borders is probably meant to refer to the borders of the whole land and not just those of the city. The Hebrew “he makes your borders peace” means that he keeps Jerusalem’s (or, Israel’s) territory safe from attack by foreign nations. It probably does not mean here internal peace, lack of strife among its people, as Biblia Dios Habla Hoy “He brings peace to your territory” has it; see also New Jerusalem Bible (and Bible en français courant) “He endows your realm with well-being.” Jerusalem is not only safe from foreign attack but is plentifully supplied with food (verse 14b). In languages in which wheat is unknown, it may be necessary to employ the most commonly used grain, such as rice, or the generic term “food.”

Quoted with permission from Bratcher, Robert G. and Reyburn, William D. A Handbook on the Book of Psalms. (UBS Helps for Translators). New York: UBS, 1991. For this and other handbooks for translators see here .