Bede : And the Lord shut him in from outside, and the flood was upon the earth forty days. Now this is the eighth day since the whole structure of the ark was completed. From which it is evident that the ark in the great mystery was completed on the tenth day of the same second month. For the first month, indeed, that ancient one which was collected from the Hebrews, can aptly represent the people of God. The second month, however, signifies the people of the New Testament. Hence it is commanded in the law, that whoever either were defiled by a dead body, or on a long journey, or preoccupied by any other necessity, could not celebrate Passover in the first month, should do so in this second month, in the blood of a lamb and with unleavened bread, on the fourteenth day in the evening. By the addition of this month we are marked, who could not previously celebrate the sacrament of the Lord's passion with the former people of God, as we were far distant from the communion of the saints, and defiled, indeed dead in sins; but who, after the sacrament of the Lord's incarnation being accomplished, came to faith, as it were, in the light of the second month we celebrate the Lord's Passover. On the tenth day of this month the ark was completed, for the Lord appearing in the flesh promised us the tenfold reward of the heavenly kingdom, granting us the ability to fulfill the Decalogue of the law, through the grace of the Holy Spirit given to us. This grace can indeed be symbolized by the number of seven days during which, after the ark was made, its entry and the advent of the flood were awaited, because surely, having received the promise of the kingdom, which is expressed by the tenfold reward, grace is given to the faithful by the Spirit, through which they can be united to the members of the holy Church. We can also correctly understand that the ark was flooded on the seventeenth day of the month and not before, because each of the faithful first ought to be marked in the faith with the sealing of true rest and the heavenly tenfold reward, that is, the image of the eternal king, and thus be admitted into the society of the Church through the washing of regeneration. Now because of the flood all the fountains of the great abyss were broken up and the floodgates, that is, the windows of heaven were opened, by the name of the great abyss the Scripture of the Old Testament is designated, which, long closed by the veil of the letter, could not open the veins of spiritual understanding to the world, but now revealed by the Lord, it provides the Church with abundant fountains of saving knowledge. The opening of the floodgates of heaven, however, signifies the outpouring of the evangelical and apostolic preaching, which clearly waters earthly hearts from above. Therefore, because we are confirmed in the faith of regeneration by the revealed words of prophecy, and by the open proclamation of the heralds of the New Testament, it is rightly said that for the making of the flood all the fountains of the great abyss were broken up and the floodgates of heaven were opened. — Commentary on Genesis (Hexaemeron) Bede : But the Lord sealed the ark from the outside, because He always protects His Church, which rejoices in the washing of sacred baptism, with heavenly defense, so that none of those whom He has predestined to life may perish in any way, and He protects it, struggling amid the waves of the world, so that it may not be overwhelmed or submerged by the pressures or delights of the world. For the Lord sends an angel encamping around those who fear Him, and He will rescue them. But on the day of judgment, the Lord encloses Noah with the inhabitants of the ark from the outside, when, with His elect gathered with Him in the house of His Father, He shuts the door of the kingdom against the entry of the lost, although late repentant, perpetually, according to that parable in the Gospel of the ten virgins, where it is said that those who were ready went in with Him to the marriage, and the door was shut, and so forth. Moreover, it is well said that it rained upon the earth for forty days and forty nights; for ten taken four times makes forty, because all guilt of sins, which is committed against the ten precepts of the law, throughout the whole world, which is contained in four parts, is washed away by the sacrament of heavenly baptism, whether that guilt pertains to days from the prosperity of things, or to nights from the adversity of things contracted. — Commentary on Genesis (Hexaemeron) Ephrem the Syrian : "The Lord shut the door before Noah," lest those left behind come at the time of the floods and break down the gate of the ark. The deluge came and "God blotted out all flesh. Only Noah was left and those that were with him in the ark." The springs of the abyss and the floodgates of heaven were open forty days and forty nights, and the "ark was afloat for one hundred fifty days." — COMMENTARY ON Genesis 6.11.2 John Chrysostom : The text goes on, "The Lord God shut the ark from the outside." Notice in this place too the considerateness in the expression "God shut the ark from the outside," to teach us that he had ensured the good man's complete safety. The reason for adding "from the outside" to "he shut" was that the good man might not be in the position of seeing the disaster occur and suffering even greater distress. I mean, if he brooded over that terrible flood and set indelibly in his mind the destruction of the human race, the complete annihilation of all brute beasts and the disappearance, as it were, of people, animals and the earth itself, he would have been disturbed and anguished. — HOMILIES ON Genesis 25.12 Justin Martyr : When 'God shut Noah into the ark,' you must not imagine that the unbegotten God Himself came down or went up from any place. For the ineffable Father and Lord of all neither has come to any place, nor walks, nor sleeps, nor rises up, but remains in His own place, wherever that is, quick to behold and quick to hear, having neither eyes nor ears, but being of indescribable might; and He sees all things, and knows all things, and none of us escapes His observation; and He is not moved or confined to a spot in the whole world, for He existed before the world was made. — Dialogue with Trypho, Chapter CXXVII