What does Genesis 8:2 mean?
In the previous verse, God started the process of drying out the earth, causing a great wind to blow over the planet. Here, we're told that He also turns the incoming deluge of water off, closing the gushing "fountains of the deep" and shutting the "windows of the heavens." The destructive rainfall of the flood lasted for 40 days (Genesis 7:12), but it's possible that a lighter rain has continued until this point in time. Those rains are "restrained," not necessarily "prevented," meaning a normal cycle of rain might have begun at this point.With no new water entering the system and a strong wind blowing, the water level begins to decrease. From the moment Noah was told to enter the ark (Genesis 7:7–9), until the ark will finally touch solid ground again (Genesis 8:4), 150 days will have passed. The land won't be ready for Noah and the animals to leave at that point, but this was probably a very welcome feeling after several months bobbing on the sea.