Darchei Shalom: Vayeishev
The 22nd of Kislev is the Yahrtzeit of Rabbi Shalom Margintu, author of Darchei Shalom. He died on November 30, 1809.
The Ramban explains that Jacob was allowed to marry sisters because they were converts, and the law is, “A convert is like a new born baby.” According to Halacha, Rachel and Leah, converts, were not considered sisters.
Bilha and Zilpa, the two handmaidens also converted. Therefore, their children were not considered the children of servants. Joseph was furious when the sons of Leah treated the other boys as servants because that reflected a rejection of the Halachic status of “ a newborn baby,” which would imply that Jacob sinned when he married sisters.
The brothers intentionally sold Joseph into slavery to insist on their point. Jacob was concerned that God allowed this to happen and took it to mean that he had been wrong to rely on that Halacha. This is why he became inconsolable.