Many people in the world were stealing. Therefore, Hashem wanted to destroy the world.Noach, a man who didn't steal, was told by Hashem to build a teiva and he and his family would be safe.
Second Part of Mabul
Hashem told Noach that the following people should go into the teivah: Noach, his wife, his children and their wives. Hashem told Noach to put 7 pairs of kosher animals and 2 pairs of non kosher animals in the teiva. Hashem told Noach that the Mabul will last 40 days and 40 nights
First Part After the Mabul
We will build a tower to the sky
Noach was 600 years old when the Mabul started. After the rain stopped pouring, the water was still on the ground for 150 days. The teiva rested on the Mountain of Ararat on the 17th of Sivan.
Second Part After the Mabul
I, Hashem, made this rainbow as a sign, a promise, that I will never make a Mabul again.
After the Mabul, Noach didn't know if the land was dry yet so he sent out a raven and it came back which meant the land was still wet. Eventually, Noach sent a dove and it came back with an olive branch so Noach knew the land started to dry. On the 27th of Cheshvan, the land was dry so Hashem commanded Noach to leave the teivah.
Noach built a mizbeach as a sign of thanks to Hashem for saving him and his family. The people of Shinar decided to make a tower to "fight" Hashem. They were punished when Hashem changed their languages.
After the mabul, Hashem made a rainbow as a promise that He will never bring a mabul again. Noach died at the age of 950.