Why did the ancient rabbis think there would be two messiahs?
Ancient rabbis studied the two names given to Rachel’s son in Genesis 35: Ben-Oni, meaning son of my suffering or sorrow, and Ben-Jamin, meaning son of my right hand, strength, or power. They concluded this pictured two messiahs: a suffering messiah and a ruling messiah, unable to see both roles embodied in one Messiah.
Les explains that in Genesis 35, Rachel dies in hard labor and names her son Ben-Oni, meaning “the son of my suffering” or “my sorrow, my heartbreak.” Jacob then names him Benjamin, meaning “the son of my right hand,” “the son of strength,” or “the son of power.” Les teaches that the ancient rabbis studied and mulled over these two names for centuries, and some concluded this must be a picture of two messiahs. Many therefore taught there would be a suffering messiah, Ben-Oni, and also a ruling messiah, Ben-Jamin. They could not picture both being embodied in the one and only Messiah.
And it came to pass, as her soul was in departing, (for she died) that she called his name Benoni: but his father called him Benjamin.