Clement of Alexandria : "Let us not then sleep, as do others, but let us watch," says the Scripture, "and be sober. For they that sleep, sleep in the night; and they that be drunken, are drunken in the night," that is, in the darkness of ignorance. "But let us who are of the day be sober. For ye are all children of the light, and children of the day; we are not of the night, nor of the darkness." But whoever of us is most solicitous for living the true life, and for entertaining noble sentiments, will keep awake for as long time as possible, reserving to himself only what in this respect is conducive to his own health. — The Instructor Book 2 John Chrysostom : "For ye are all sons of light, and sons of the day." And how is it possible to be "sons of the day"? Just as it is said, "sons of destruction" and "sons of hell." Wherefore Christ also said to the Pharisees, "Woe unto you-for ye compass sea and land to make one proselyte, and when he is become so, ye make him a son of hell." (Matt. xxiii. 15.) And again Paul said, "For which things' sake cometh the wrath of God upon the sons of disobedience." (Col. iii. 6.) That is, those who do the works of hell and the works of disobedience. So also sons of God are those who do things pleasing to God; so also sons of day and sons of light, those who do the works of light. "And we are not of the night nor of darkness." — Homily on 1 Thessalonians 9 Origen of Alexandria : If you wish to see Jesus transfigured before those who went up on the mountain with him, behold with me the Jesus in the Gospels as more simply understood. This is Jesus, as one might say, known "according to the flesh" by those who do not go up through uplifting words and works to the holy mountain of wisdom. Behold him with me as known in his divinity by means of all of the Gospels, beheld in the form of God according to the knowledge that his companions had. For before them Jesus is transfigured, but not to any of those who are below. But when he is transfigured, his face also shines as the sun, so that he may be manifested to the children of light. These have put off the works of darkness and have put on the armor of light and are no longer the children of darkness or night, but have become sons of the day and walk honestly as in the day. Being manifested, he will shine for them not only as the sun, but as the son of righteousness. — COMMENTARY ON Matthew 12.37 Tertullian : But when he urges us not to give place to evil, he does not offer the suggestion that we should take to our heels, he only teaches that passion should be kept under restraint; and if he says that the time must be redeemed, because the days are evil, he wishes us to gain a lengthening of life, not by flight, but by wisdom. Besides, he who bids us shine as sons of light, does not bid us hide away out of sight as sons of darkness. — On Flight in Persecution