Because like Adam and Eve in the first creation story, Noah is told to be fruitful and multiply.

因为就像第一个创世故事里的亚当和夏娃，诺亚被告知要多子多孙。

youdao

And you, be ye fruitful, and multiply; bring forth abundantly in the earth, and multiply therein.

你们要生养众多，在地上昌盛繁茂。

youdao

And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.

1：22神就赐福给这一切，说，滋生繁多，充满海中的水。雀鸟也要多生在地上。

youdao

And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.

1：22神就赐福给这一切，说，滋生繁多，充满海中的水。雀鸟也要多生在地上。

youdao