Genesis 7:10 "And it came to pass after seven days, that the waters of the flood were upon the earth."

For yet seven days, God spoke these words probably on the seventh or Sabbath day, and the days of the ensuing week were employed in entering the ark, in embarking the mighty troop, for whose reception ample provision had been already made.

As Noah prepared the ark by faith in the warning given that the flood would come, so he went into it, by faith in this warning that it would come quickly. And on the day Noah was securely fixed in the ark, the fountains of the great deep were broken up.

The windows of heaven were opened, and the waters which were above the firmament, that is, in the air, were poured out upon the earth. The rain comes down in drops; but such rains fell then, as were never known before or since.

Genesis 7:11 "In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened."

This rain did not just fall from the sky, but it came from springs and openings in the earth as well. Water came from everywhere. 

Genesis 7:12 "And the rain was upon the earth forty days and forty nights."

Genesis 7:13 "In the selfsame day entered Noah, and Shem, and Ham, and Japheth, the sons of Noah, and Noah's wife, and the three wives of his sons with them, into the ark;"

“Entered Noah, and Shem, and Ham, and Japheth, the sons of Noah.” Not inconsistent with verses 4 and 5, which do not necessarily imply that the actual entry was made seven days before the Flood; but merely that Noah then began to carry out the Divine instructions.

The threefold recital of the entry: first in connection with the invitation or command (verse 5), and again in the actual process during the seven days (verse 7), and finally on the day when the Flood began (verse 15).

Genesis 7:14-15 "They, and every beast after his kind, and all the cattle after their kind, and every creeping thing that creepeth upon the earth after his kind, and every fowl after his kind, every bird of every sort." "And they went in unto Noah into the ark, two and two of all flesh, wherein [is] the breath of life."

There is a simple grandeur in the threefold description of the entrance of Noah and his family and animals going into the ark, first in the command, next in the actual process during the seven days, and lastly, in the completed act on the seventh day.

"Every living thing after its kind" – all of the wild animals did not just show up a Noah’s door. God moved upon three pairs plus one for all of the “clean” animals and two pairs of the unclean animals. The free range of the animals would have made it impossible for Noah to have gone forth to gather them up. So this was a Divine Act of God.

"And the Lord shut him in." This is a fitting close to the scene. The whole work was manifestly the Lord's doing, from first to last. And it was God who shut the door to the Ark