1 Samuel 3:9

15. For now the boy, having been instructed, is sent to the knowledge of divine speech, when the chosen one, subject to the counsel of his superior, is prepared for knowing spiritual things. And indeed for him to sleep is to rest in the desire of eternal life, when, that is, to the soul now thirsting for heavenly things alone, all present things are held in contempt, so that the more eagerly everything corporeal is driven from its attention, the more abundantly it is filled with the love of invisible things. And it should be noted that he is now commanded to return to the rest of sleep four times, because while we carelessly occupy ourselves with this world regarding visible things, we are awake in deed, speech, and thought. Therefore we are commanded to sleep three times, so that we may be prepared for the knowledge of heavenly things through rest from works, silence of the mouth, and the rejection of superfluous thoughts. But in the fourth place we are sent to sleep when by the permission of our superiors we are commanded to cease even from useful ministry, so that while we are hindered by no care of anxiety, the mind may gather itself entirely to the contemplation of the heavenly vision.

But to him whom he understood was to be called, he also supplied counsel, saying: (Verse 9.) "Go and sleep, and if he calls you again, you shall say: Speak, Lord, for your servant hears." 16. Enough has already been shown, I believe, that the sleep of Samuel signifies the quiet of interior meditation. This sleep is indeed commanded to Samuel by Eli, because the teacher is taught through sacred Scripture to devote himself to contemplating interior mysteries. But what does it mean that each time Samuel is called, he is sent back to sleep, and yet he is by no means yet commanded to say to God: "Speak, Lord, for your servant hears"? For there he is commanded to sleep, but not yet to speak; here, however, along with the obedience of sleep, permission to speak is also enjoined. There also, when sent to sleep, it is not said "Go," but "Return"; here likewise it is by no means said "Return," but "Go." For what does such variety in commanding mean? We recognize this variety more clearly, of course, if we attend to what sleep signifies for Samuel in this passage. And since we have referred the earlier modes of sleep to the testing of the gifts of holy love (above, nos. 11, 12), what is it for Samuel in this passage—that is, for the new preacher—to sleep, except to possess those same gifts, now tested and known, with the repose of security? Rightly, therefore, previously it was not said to him "Go," but "Return"; now, however, not "Return," but "Go." For he who was still examining was commanded to return, so that with tranquility of mind he might test another gift, having already recognized another by that same quiet of mind. But to him, because he had now proved all things by examining them, "Go" is said, because he was now being sent with secure intention to possess what he had come to know. Why then is sleep first commanded without speech, but now sleep with speech, unless because it was not permitted to say "Speak" except to one who was certain with true knowledge that the one speaking to the affections of his mind was God? Therefore it is not said to one who is still examining, because unless he perfectly discerns the one speaking within, he ought not to desire spiritual speech still uncertain to him, nor receive it as though it were certain. For to say to God in one's mind "Speak" is to receive his interior inspiration with security. Therefore this belongs to…