The flood in the days of Noah is one of the most iconic Bible stories. One thing to note from Chapter 5 of Genesis is Methuselah's name can mean a few different things, but one of the interpretations of his name is "he dies. It happens." It is significant to see the flood coincides with the death of Methuselah. I have always wondered if he died during the flood, but the Bible is silent on that issue. In Genesis chapters 6-9, we hear the account of the flood. It grieved God that he made men on the earth. "My Spirit shall not abide in man forever, for he is flesh; his days shall be 120 years." People occasionally argue that God meant humankind would not live past 120 years of age from that point forward. This is not the meaning of the text, as many people, including Abraham, Isaac, and Jacob, all lived longer than 120 years. It is more likely that God has numbered the years of humanity on the earth at 120 years left before he brings the flood. God is setting a timer until the day the flood would ravage the earth. Others will suggest it was a period specified by God because that's how long it would take Noah to build the ark. This is also not supported by the text, and the text actually contradicts this idea. Noah was 600 years old when the flood came to the earth. Noah was about 500 years old when he had his sons, yet when God told Noah about the coming judgment in flood form, he gave instructions to Noah and Noah's sons, along with their wives. So Noah and his sons built the ark in less than 100 years, and since they were already grown and married, it is probably closer to 50-60 years or less to build the ark. But that's just speculation...