What does Genesis 8:10 mean?

In the previous verses, Noah sent out birds in an effort to locate dry land. Sailors in ancient days would release a land-dwelling bird in order to locate land. The bird would fly high to look for a place to go, and head in that direction if there was an island or shore nearby. If the bird came back, it meant there was nowhere close for it to land other than the ship.

Noah has already sent out a raven and then a dove from the ark. If these birds did not return, Noah could assume that they had found land where they'd prefer to stay; this would mean the earth was drying out enough to begin to support life again. The first dove comes back empty-handed (Genesis 8:9). Noah waits seven days between these missions, suggesting that he is keeping to the same seven-day weekly calendar used prior to the flood. Some scholars suggest that Noah even observed a Sabbath in some way.