When God ordained marriage as described in Genesis, there is a set form for marriage: one man for one woman in a stable, lasting, fruitful relationship of mutual support for one lifetime.
What Does the Bible Teach About Polygamy PP21 And the Lord God caused a deep sleep to fall on Adam, and he slept; and He took one of his ribs, and closed up the flesh in its place. 22 Then the rib which the Lord God had taken from man He made into a woman, and He brought her to the man.
23 And Adam said:
“This is now bone of my bones
And flesh of my flesh;
She shall be called Woman,
Because she was taken out of Man.”24 Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh.