John Calvin Commentary Genesis 30:15

"And she said unto her, Is it a small matter that thou hast taken away my husband? and wouldest thou take away my son`s mandrakes also? And Rachel said, Therefore he shall lie with thee to-night for thy son`s mandrakes." — Genesis 30:15 (ASV)

Is it a small matter that you have taken my husband? Moses leaves more for his readers to reflect upon than he expresses in words; namely, that Jacob’s house had been filled with contentions and disputes. For Leah speaks haughtily, because her mind had long been so exasperated that she could not address her sister mildly and courteously.

Perhaps the sisters were not so contentious by nature; but God allowed them to contend with each other, so that the punishment of polygamy might be shown to posterity. And it is not to be doubted that this domestic private quarrel, indeed, hostile dissension, brought great grief and torment to the holy man. But the reason why he found himself so distracted by opposing parties was that, against all right, he had broken the unity of the conjugal bond.