Matthew 9:38

Then to signify how great the gift is, He saith, "Pray ye the Lord of the harvest;" and indirectly declares it to be His own prerogative. For after having said, "Pray ye the Lord of the harvest;" when they had not made any entreaty nor prayer, He Himself at once ordains them, reminding them also of the sayings of John, of the threshing floor, and of the Person winnowing, and of the chaff, and of the wheat. Whence it is evident that Himself is the husbandman, Himself the Lord of the harvest, Himself the master and owner of the prophets. For if He sent them to reap, clearly it was not to reap what belongs to another, but what Himself had sown by the prophets. But not in this way only was He indirectly encouraging them, in calling their ministry a harvest; but also by making them able for the ministry.

But consider, dearest brothers, consider what is said: "Pray the Lord of the harvest, that he send laborers into his harvest." Petition on our behalf, that we may be able to work worthily for you, lest our tongue grow sluggish from exhortation, lest after we have taken up the place of preaching, our silence condemn us before the just judge. For often the tongue of preachers is restrained because of their own wickedness; but often indeed it happens through the fault of those subject to them that the word of preaching is withdrawn from those who are in charge. Indeed the tongue of preachers is restrained because of their own wickedness, as the Psalmist says: "But to the sinner God said: Why do you declare my justices?" And again, because of the fault of those subject to them, the voice of preachers is forbidden, as the Lord says to Ezekiel: "I will make your tongue cleave to your palate, and you shall be mute, and not as a man who rebukes, because it is a provoking house." As if he were to say openly: Therefore the word of preaching is taken from you, because while the people provoke me in their actions, they are not worthy to receive the exhortation of truth. From whose fault, therefore, the word is withdrawn from the preacher is not easily known. But it is known most certainly that the silence of the Pastor sometimes harms himself, but always harms those subject to him.