Original Text
And when Methuselah had heard the words of his father Enoch--for he had shown to him everything in secret--he returned and showed (them) to him and called the name of that son Noah; for he will comfort the earth after all the destruction. CVIII. AN APPENDIX TO THE BOOK OF ENOCH.
Simple English
When Methuselah heard his father Enoch's words-since Enoch had revealed everything to him in private-he went back and shared it with Enoch. They named the child Noah, because he would bring comfort to the earth after all the destruction.