Job 38:40

“When they couch in their dens, and lie in wait in their caves. 26. For when the holy Apostles did not at all rise up against the limbs of the devil in the voice of bold preaching, and, not being yet strengthened after the Lord's Passion with the outpouring of the Holy Spirit, did not preach their Redeemer with firm authority, they were still lying in wait, as it were, in dens against their adversaries. For when the doors were closed, the whelps who were about to ravage the world were couching, as it were, in certain secret caves: in order that they might afterwards boldly seize the prey of souls, of whom it was then certain, from their very concealment, that they were afraid of the assault of the world on themselves. These whelps in ambush with those closed doors sought for the death of our death, that so they might destroy our guilt, and kill all the life of sin within us. To the chief of these, that famished, but still vigorous whelp, it is said, when the Gentiles had been set before him by the linen sheet, as though the prey had been pointed out to him, Kill and eat. [Acts 10, 13] These whelps, as though they were still weak, are ordered to couch in their dens, when it is said to them by the voice of the Lord, Tarry ye here in the city until ye be endowed with power from on high. [Luke 24, 49] Are not they rightly called the whelps of the lioness, who, having been born in the Church, seized with their mouth the opposing world? 27. And these things we know were done by the holy Apostles, these also we now see done by perfect teachers. For though they are the fathers of the people that follow them, yet are they the sons of those who go before; whence they are not improperly called whelps. Or certainly because though they are the teachers of certain of the faithful, yet they boast that they are the disciples of the Church universal. The Lord, therefore, seizes the prey for the lioness, because by the virtue of His inspiration He seizes the life of offenders from error; and He fills the soul of her whelps, because by the conversion of many He satisfies the holy longings of teachers. Of which whelps it is well subjoined; When they couch in their dens, and lie in wait in their caves. For all seasons are not fitted for teaching. For the value of sayings is commonly lost, if they are brought forward out of season. And frequently even that which is said gently, is animated by the concurrence of a fitting season. He therefore knows how to speak well, who knows also how to be silent at proper times. For of what use is it to reprove an angry man, at the time when with estranged mind he is not only unable to listen to the words of others, but is hardly able to hear himself. For he who reproves an angry man by inveighing against him, inflicts, as it were, blows on a drunken man who feels them not. Teaching therefore, in order to be able to reach the hearts of the hearers, must consider what seasons are suitable to it. It is therefore well said of these whelps, When they couch in their dens, and lie in wait in their cares. For when holy teachers perceive things to be reproved, and yet confine themselves in their thoughts by silence, they lurk, as it were, in caves, and cover themselves, as if in dens; because they are concealed in their own thoughts. But when they have found a fit season, they suddenly leap forth, they suppress nothing which ought to be said, and seize with the grasp of severe reproof the neck of the haughty. The Lord is therefore daily seizing the prey for this lioness, whether by Apostles, or by teachers whom He has appointed in the place of the Apostles; and by those whom He has seized, He ceases not to seize others also. For the righteous seize the sinners of this world for this purpose, that others also may be snatched from the world by them when they are converted. Whence the Gentile world itself also, which was seized by the holy mouth of the Apostles, is now ravenous after others, with the same hunger, as it knows that it was itself desired by the Apostles.”

“This does not seem very difficult when they range through many different places, but when they stay in the same place, it is difficult either from necessity of feeding the cubs which he discusses saying, "when they lie in their dens," or because they are waiting in ambush for some other animals, "and lie in wait in the hollows," to capture animals.”