Augustine of Hippo

But you, "O elect people," set in the firmament of the world, who have forsaken everything that you may follow the Lord, follow him now and confound the mighty! Follow him, O beautiful feet, and shine in the firmament, that the heavens may declare his glory, dividing the light of the perfect ones—though not yet so perfect as the angels—from the darkness of the little ones, who are nevertheless not utterly despised.

Confessions 13.19 ↗

Jerome

How beautiful upon the mountains are the feet of the messenger of good news, who announces peace, who brings good news, who announces salvation, who says to Zion, 'Your God reigns.' The voice of your watchmen—they lift up their voice; together they sing for joy; for eye to eye they see the return of the Lord to Zion. …

Commentary on Isaiah ↗

Thomas Aquinas

How beautiful. Here he proclaims joy to the liberated. And first, he describes their joy as to the reception of messengers, who, coming from Chaldea, announced it to them: beautiful, for it was beautiful and pleasant to the people to hear them announcing such things; upon the mountains, so that many would hear them; that preaches, publicly, peace, restored by Cyrus, good, of promised assistance, salvation, from captivity; your God shall reign, as though from then on, God alone will reign in you because you will worship him in the …

Commentary on Isaiah ↗