Bede : And the fountains of the deep were closed, and the windows of heaven, and the rains from heaven were restrained, and the waters returned from the earth, going and coming, and they began to decrease after one hundred and fifty days. What is said, that the waters returned from the earth going and coming, clearly indicates according to the letter that all the courses of rivers and streams return through the hidden veins of the earth to the matrix of the abyss, according to Solomon: All the rivers run into the sea, yet the sea does not overflow; to the place where the rivers go forth, they return so that they may flow again (Ecclesiastes I, 7). Mystically, however, after one hundred and fifty days, the fountains of the deep and the windows of heaven are closed, the rains ceasing, the waters return, because the words of the sacred oracle, after having trained us in the faith and hope of eternal rest and immortality, will cease to teach us further, because they will have nothing greater to promise, after having perfected us in the immortal glory of flesh and spirit and led us to the blessed vision of our Creator. Hence it is well that the book of Psalms, which is contained in the number of one hundred and fifty, is completed in divine praise. Indeed, the beginning of blessedness takes its rise from continence and meditation on the divine law, saying: Blessed is the man who does not walk in the counsel of the wicked (Psalm I, 1), and the rest. Near the end, however, it commends the new joys of the future age, saying, and at the very end consummates all in praise of God: Sing to the Lord a new song, praise in the assembly of the saints (Psalm CXLIX, 1); thus concluding; Let everything that has breath praise the Lord (Psalm CL, 6). This hundred and fiftieth psalm is rightfully sung entirely in praise of God, and completed, because evidently the sum of all our blessedness is in this, that dwelling in His house we may endlessly praise Him. — Commentary on Genesis (Hexaemeron) Jerome : (Chapter 8, Verse 2) And the water subsided, and the fountains of the deep were revealed, and the floodgates of heaven were opened. The interpreters have translated the phrase 'fountains of the deep were revealed' as 'the closed and sealed fountains were opened'. And regarding the following phrase: 'the water subsided from the earth', it is written that 'the waters returned from the earth, going and coming' (Ecclesiastes 1:7). Note, according to Ecclesiastes, that all waters and torrents return to the hidden veins of the abyss. — Hebrew Questions on Genesis