13 And God said unto Noah, The end of all flesh is come before me; for the earth is filled with violence through them; and, behold, I will destroy them with the earth. 
13 So God said to Noah, "I am going to put an end to all people, for the earth is filled with violence because of them. I am surely going to destroy both them and the earth.
13 And God said to Noah, "I have determined to make an end of all flesh,
13 God said to Noah, "It's all over. It's the end of the human race. The violence is everywhere; I'm making a clean sweep.
13 And God said to Noah, "The end of all flesh has come before Me, for the earth is filled with violence through them; and behold, I will destroy them with the earth.
13 So God said to Noah, "I have decided to destroy all living creatures, for they have filled the earth with violence. Yes, I will wipe them all out along with the earth!
Matthew Henry's Commentary on Genesis 6:13
Commentary on Genesis 6:12-21
(Read Genesis 6:12-21)
God told Noah his purpose to destroy the wicked world by water. The secret of the Lord is with them that fear him, Psalm 25:14. It is with all believers, enabling them to understand and apply the declarations and warnings of the written word. God chose to do it by a flood of waters, which should drown the world. As he chooses the rod with which he corrects his children, so he chooses the sword with which he cuts off his enemies. God established his covenant with Noah. This is the first place in the Bible where the word 'covenant' is found; it seems to mean, 1. The covenant of providence; that the course of nature shall be continued to the end of time. 2. The covenant of grace; that God would be a God to Noah, and that out of his seed God would take to himself a people. God directed Noah to make an ark. This ark was like the hulk of a ship, fitted to float upon the waters. It was very large, half the size of St. Paul's cathedral, and would hold more than eighteen of the largest ships now used. God could have secured Noah without putting him to any care, or pains, or trouble; but employed him in making that which was to be the means to preserve him, for the trial of his faith and obedience. Both the providence of God, and the grace of God, own and crown the obedient and diligent. God gave Noah particular orders how to make the ark, which could not therefore but be well fitted for the purpose. God promised Noah that he and his family should be kept alive in the ark. What we do in obedience to God, we and our families are likely to have the benefit of. The piety of parents gets their children good in this life, and furthers them in the way to eternal life, if they improve it.