The Lord revealed to Noah the seven-day countdown,
“For after seven more days I will cause it to rain on the earth…” (Genesis 7.4).
Moses shows that the Lord kept His word,
“And it came to pass after seven days that the waters of the flood were on the earth. In the six hundredth year of Noah’s life, in the second month, the seventeenth day of the month, on that day all the fountains of the great deep were broken up, and the windows of heaven were opened. And the rain was on the earth forty days and forty nights” (Genesis 7.10–12).
He said what He meant, and meant what He said.
This passage also brings up another interesting point, that is, the number 40, which comes up again and again throughout Scripture, and it is interesting to see its association here with the number 7!