Genesis 30:1 - The Popular Commentary by Paul E. Kretzmann

And when Rachel saw that she bare Jacob no children, Rachel envied her sister, and said unto Jacob, Give me children, or else I die. Barrenness was considered a special punishment and curse of God in the Old Testament, especially in the families of the patriarchs, in whose case the longing for the Messiah intensified the desire for children. Rachel, therefore, seeing her sister Leah bearing one son after the other, was filled with envy and impatience, believing, apparently, that all her prayers for offspring were vain. That explains her outburst of temper, which caused her to state that she would die from dejection and grief unless Jacob would manage to bring her children.