12 “Day and night there will compass it upon the walls thereof iniquity, and labour.” “Upon the walls thereof;” upon the fortifications thereof, holding as it were the heads thereof, the noble men thereof. If that noble man were a Christian, not one would remain a pagan! Oft-times men say, “no one would remain a pagan, if he were a Christian.” Ofttimes men say, “If he too were made a Christian, who would remain a pagan?” Because therefore not yet they are made Christians, as if walls they are of that city unbelieving and contradicting.
How long shall these walls stand? Not always shall they stand. The Ark is going around the walls of Jericho: there shall come a time at the seventh going round of the Ark, when all the walls of the city unbelieving and contradicting shall fall. Until it come to pass, this man is being troubled in his exercise; and enduring the remains of men contradicting, he would choose wings for flying away, would choose the rest of the desert. Yea let him continue amid men contradicting, let him endure menaces, drink revilings, and look for Him that will save him from weakness of mind and tempest: let him look upon the Head, the pattern for his life, let him be made calm in hope, even if he is troubled in fact.
“Day and night there will compass it upon the walls thereof iniquity; and labour in the midst thereof and injustice.” And for this reason labour is there, because iniquity is there: because injustice is there, therefore also labour is there. But let them hear him stretching forth hands. “Come unto Me, all you that labour.” You cry, you contradict, you revile: He on the contrary, “Come unto Me, all you that labour,” in your pride, and you shall rest in My humility. “Learn of Me,” He says, “for meek I am and humble in heart, and you shall find rest unto your souls.” For whence do they labour, but because they are not meek and humble in heart? God humble was made, let man blush to be proud.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)