Then Judah said to Onan, Go in to your brother's wife and do what it is right for a husband's brother to do; make her your wife and get offspring for your brother.
And the older daughter said to her sister, Our father is old, and there is no man to be a husband to us in the natural way:
You may not have sex relations with your brother's wife, for she is your brother's.
But Naomi said, Go back, my daughters; why will you come with me? Have I more sons in my body, to become your husbands?