And it came to pass at the end of forty days, that Noah opened the window of the ark which he had made:

Jamieson-Fausset-Brown Bible Commentary

6. at the end of forty days-It is easy to imagine the ardent longing Noah and his family must have felt to enjoy again the sight of land as well as breathe the fresh air; and it was perfectly consistent with faith and patience to make inquiries whether the earth was yet ready.

Matthew Henry's Concise Commentary

8:4-12 The ark rested upon a mountain, whither it was directed by the wise and gracious providence of God, that might rest the sooner. God has times and places of rest for his people after their tossing; and many times he provides for their seasonable and comfortable settlement, without their own contrivance, and quite beyond their own foresight. God had told Noah when the flood would come, yet he did not give him an account by revelation, at what times and by what steps it should go away. The knowledge of the former was necessary to his preparing the ark; but the knowledge of the latter would serve only to gratify curiosity; and concealing it from him would exercise his faith and patience. Noah sent forth a raven from the ark, which went flying about, and feeding on the carcasses that floated. Noah then sent forth a dove, which returned the first time without good news; but the second time, she brought an olive leaf in her bill, plucked off, plainly showing that trees, fruit trees, began to appear above water. Noah sent forth the dove the second time, seven days after the first, and the third time was after seven days also; probably on the sabbath day. Having kept the sabbath with his little church, he expected especial blessings from Heaven, and inquired concerning them. The dove is an emblem of a gracious soul, that, finding no solid peace of satisfaction in this deluged, defiling world, returns to Christ as to its ark, as to its Noah, its rest. The defiling world, returns to Christ as to its ark, as to its Noah, its rest. The carnal heart, like the raven, takes up with the world, and feeds on the carrion it finds there; but return thou to my rest, O my soul; to thy Noah, so the word is, Ps 116:7. And as Noah put forth his hand, and took the dove, and pulled her to him, into the ark, so Christ will save, and help, and welcome those that flee to him for rest.