What does Genesis 31:40 mean?

Jacob is describing his twenty years of faithful and diligent service to Laban, who had condemned him for leaving without notice. Worse, Laban had accused Jacob of outright theft, a claim seemingly disproven when Laban's search comes up empty (Genesis 31:30–35). Seizing the opportunity to put Laban in his place, Jacob blasts his father-in-law for his abusive, dishonest, cheating ways (Genesis 29:20–28; 30:31–36). In part, Jacob makes the point that he served Laban far better than any employer had a right to expect, even though Laban took repeated advantage of him.

In addition to protecting Laban's flocks and paying for losses due to animal attacks himself, Jacob points out that the work was difficult. As a shepherd, he endured blistering hot days, freezing cold nights, and too little sleep. Jacob's purpose point in all of this is to prove that he never cheated Laban in any way, but served him well. He did not deserve the mistreatment Laban had given to him, nor the accusations Laban has brought.