דברי הימים א, פרק ה׳, פסוק ב׳

A natural birthright typically carries both the mantle of leadership and a double share of material wealth. However, because of the actions of the biological firstborn, Reuben, these privileges were taken away and divided between two different brothers. Judah possessed the most prominent and important personality among the siblings [ביאור שטיינזלץ]. Despite not being the firstborn, he prevailed over the others, including Joseph, and ultimately secured the royal crown [מצודת דוד, מלבי״ם]. This royal destiny was established during Jacob's final blessings, where he compared Judah to a lion [רש״י]. Jacob intended for the permanent dynasty of leadership and royalty for the nation of Israel to emerge from Judah's line [רד״ק, מצודת דוד]. As the recognized leader who would actively guide the people [רש״י], Judah is mentioned first in the historical record, honoring the supreme importance of the monarchy [מצודת דוד, חומת אנך].

While Judah assumed the role of the leader, the legal and social status of the birthright was transferred to Joseph. The primary approach among commentators is that this status mainly consisted of the right to inherit a double portion of the land [רוב הפרשנים]. This material birthright was fully realized when Joseph's two sons were elevated to the status of separate tribes, each receiving their own independent territory [רש״י, רד״ק].

The removal of the birthright from Reuben and its transfer to Joseph also carries a profound legal significance. This shift serves as proof that the Patriarchs were governed by the specific laws of the Torah rather than the universal laws given to the descendants of Noah. Under the unique framework of Israelite law, Reuben's sin involving his father's bed was viewed as less severe from a strict legal standpoint. Consequently, the stripping of his birthright acted as a necessary spiritual correction, providing him with a pathway to atonement for his actions [מלבי״ם].