What does Genesis 7:10 mean?

Finally, the flood begins. It comes at exactly the time God said it would in verse 4. God's destruction of life on the earth, and the salvation of life from that destruction, has begun.

Here, as in prior verses, the flood is said to come on "the earth," using the Hebrew term 'erets. This term is often used in a local or regional sense. The Bible uses a different Hebrew word, tebel, when specifically referring to the entire planet. This, along with a few other aspects of the language used, leads some Bible scholars to interpret this as a local flood. In other words, an event covering the regions inhabited by mankind, but not necessarily the entire planet. Since the intent is the destruction of sinful man (Genesis 6:5), this ultimately makes little difference as far as the story of the flood itself is concerned. God judges mankind with the flood, and only Noah and his family survive (Genesis 6:18).

It's interesting to notice that God continues to operate within the seven-day cycle He established when He created the earth. Noah will adhere to a seven-day cycle when sending out the birds to look for dry land in chapter 8. Israel, too, will conform to God's seven-day cycle when the nation is established later in the book of Genesis.