Jacob's Wives Are Fruitful As Yahweh Had Promised (Genesis 29:31 to Genesis 30:24)
‘And Yahweh saw that Leah was unloved and he opened her womb. But Rachel was barren.'
The bearing of a son was of vital importance in Jacob's day for such a son or sons would inherit the family tribe and wealth and maintain the family name. A man felt he lived on in his sons. They would also eventually strengthen Jacob's position. Thus Leah is delighted when she bears not one but four sons. But Rachel, who was barren was devastated.
The writer sees what has happened to Leah as a sign of God's goodness to her. But it is noteworthy that he does not directly suggest that Rachel's barrenness is God's handywork, although others would see it that way.
“Unloved.” The word regularly means ‘hated' but the previous verse suggests that although Jacob preferred Rachel he still had some love for Leah. Thus the translation ‘unloved' is more likely. There is no suggestion that he treated her badly (contrast his words to his beloved Rachel in 30:2).