The Lord did not will that the jubilee-buccinae then be sounded because it was the beginning of a jubilee year. But: First, that he might show that the Jericho…
(col. 749)
…[the Jericho] war would bring the Israelites no sadness, but very much joy and gladness. Secondly, that they might understand they were now being restored into the inheritance once promised, and into the land held by unjust invaders. Thirdly, just as in the jubilee year the fruits which the untilled earth yields are common to all — and the rich man plucks no more of them for himself than the poor man and the beggar — so in the Jericho victory the powerful, the strong, and the wealthy claims for himself no greater share than any poor wretch, weak and needy. The whole victory is to be ascribed to God: there was no human labor, no battle, no blood, and no sweat. Fourthly, the jubilee-buccinae were cheap, if we regard the material — of ram’s horn, namely, as was said above (q. 4); horns, in which [is there] anything splendid or rare? Yet these God chose above all the silver and splendid trumpets — willing that by their sounding the men of Jericho be brought into admiration and stupor, and the whole city at last be shaken; [willing that it] be stormed and taken, not without great mysteries indeed. “For see,” says the Apostle (1 Corinthians 1:26), “your calling, brethren: that [there are] not many wise according to the flesh, not many powerful, not many noble; but the foolish things of the world God has chosen, that he may confound the wise; and the weak things of the world God has chosen, that he may confound the strong; and the base things of the world, and the contemptible, God has chosen, and the things that are not, that he might bring to nought the things that are: that no flesh should glory in his sight.”
Who [but the Apostles] utterly stupefied, struck down, and overturned the whole globe of lands — one Jericho, as it were, most full of idols, of pleasures, and of all crimes — by their voice and their clangor? Were they not little men, commended by no nation, no number, no praise of garments, wealth, or pedigrees? — but in appearance most abject and most contemptible, worn out with labors, hunger, thirst, heat, cold, and the utmost want of all things, and most wretched? They were horns — and ram’s horns at that — which a small animal yields, a cheap shepherd supplies, [and] a lowly craftsman hollows and bores. O the counsels of God! O the power, which exerts itself through the most despicable instruments, and works such great and wondrous things! But of the mystical sound of these trumpets there will again be another place.