Charles Spurgeon Commentary Genesis 7:12-13

"And the rain was upon the earth forty days and forty nights. In the selfsame day entered Noah, and Shem, and Ham, and Japheth, the sons of Noah, and Noah`s wife, and the three wives of his sons with them, into the ark;" — Genesis 7:12-13 (ASV)

These eight persons are very carefully mentioned. The Lord knoweth them that are his, and they shall be mine, saith the Lord of hosts, in that day when I make up – or, shut up – my jewels, as he was about to do in the case. In similar fashion, God makes a very careful enumeration of all those who believe in him, precious are they in his sight, and they shall be preserved when all others are destroyed.