Genesis 30:41
And it came to pass, whensoever the stronger cattle did conceive, that Jacob laid the rods before the eyes of the cattle in the gutters, that they might conceive among the rods. And it came to pass, whensoever the stronger cattle did conceive, that Jacob laid the rods before the eyes of the cattle in the gutters, that they might conceive among the rods.
The verse belongs to Jacob's sojourn with Laban in Haran in Padan-aram, covering his marriages, his stay with Laban, the time his sons were being born, and his departure from Syria for Palestine. It falls in the time when he was serving fourteen years for his two wives, Laban's two daughters.
In the verse Jacob is at work as a herdsman caring for flocks and cattle, laying the rods before the eyes of the stronger cattle in the gutters at conception that they might conceive among the rods, in order to secure the stronger animals for himself. This was selfish plotting to gain advantage. Despite Jacob's selfishness and unfaithfulness, and despite Laban's efforts to deprive him of his right, God cared for Jacob and prospered and blessed his work with abundant flocks and herds. That prosperity was among the temporal blessings included in his birthright.
His plotting was part of his checkered and unsatisfactory experience of overreaching and supplanting others, which brought consequent suffering upon himself. He met overreaching in return, showing that God's providence, though seeming slow, brings retribution sooner or later.
The chapter containing the verse gives an example of a plain violation of the marriage institution by the patriarchs, but such violation does not undo the sacred character of marriage. Violating the Sabbath would not destroy the Sabbath, and so violating marriage does not destroy marriage. Marriage was made for man before the fall, its sanctity is not derived from the Decalogue, and the seventh commandment guards its sacredness. Jacob's care of his flocks and cattle shows that tending stock, including feeding, watering, milking, and other care needed for the life and welfare of people and animals, is necessary work that must be performed on the Sabbath the same as on any day, always reduced to a practical, merciful minimum.