What is the Islamic legal perspective on the favoritism shown by our master Jacob (peace be upon him) towards his two sons, Joseph and his brother? And has Islam prohibited a parent from feeling a natural inclination towards one child over others, even if they are unable to prevent such a feeling?

Jacob (peace be upon him) did not favor his son Joseph with gifts, rather it was a heartfelt love for which a person is not held accountable. Love and the inclination of the heart are matters beyond a person's control, unlike favoritism in gifts and similar things that a person possesses, where favoritism is forbidden without a valid reason. A parent should strive for justice among their children in every apparent matter to prevent jealousy, envy, and hatred.