Why did the first son of Jacob did not receive the first son blessing?

Jacob's first son, Reuben, lost his birthright and the associated blessings due to his actions. He committed a serious offense by sleeping with Bilhah, his father's concubine, which led Jacob to proclaim that Reuben would not Excel (Genesis 49:3-4). Instead, the blessing was given to Joseph, Jacob's favored son, due to his integrity and leadership qualities. This shift illustrates the importance of character and conduct in receiving blessings in biblical tradition.