Peace be within thy walls
The word say might be supplied; for this, with the following, seem to be petitions the psalmist puts into the mouths of those he desires to pray for Jerusalem's peace; and he directs them to pray in this manner, to take with them such words as these, and pray to the Lord. Jerusalem was a walled city, and so is the church of God; God himself is a wall of fire around her; salvation by Christ is as walls and bulwarks to her; the power and providence of God protect her: within these walls the people of God have a place and a name; all the inhabitants of Zion in common are included in this petition, and peace is wished for them all; let their condition and circumstances be what they may, be they high or low, rich or poor, stronger or weaker believers, children, young men, or fathers. Some render it, "in thine army", as the Targum, and other Jewish writers; in the church's militia, all saints being soldiers and in a warfare state; and here success to their arms against sin, Satan, and the world, is wished for;
[and] prosperity within thy palaces:
as there were palaces in Jerusalem for the king, the nobles, and great men in the land; so there are in the church of God, where he is known, for a refuge; even the meanest places in it are preferable to the palaces of the greatest monarchs see ( Psalms 48:3 ) ( 84:10 ) , And here indeed all the saints are kings, and have their palaces; but particularly there are some who are set in the first place in the church, and over others in the Lord; who are their guides and governors, and are in office relation to the church as pastors and deacons now, as there were priests and Levites before: and the prosperity of these is to be prayed for, the good of the whole church being involved therein.