Amminadab, son of Ram, was from the tribe of Judah, and a grandfather of all the high priests and the progenitor to Davidic dynasty of Israel. Through Elisheba, his daughter, he is twice the ancestor of Mary, the mother of Jesus.
Amminadab [Heb: עמינדב = "My people are generous."] was the son of Ram, born into a time of prosperity in the land of Egypt. It seems that his father felt it necessary to remind his neighbors that the sons of Israel were responsible for the good fortunes that had come Egypt, their host country. Times were about to change, however, as a dynasty had arisen that did not remember the good that Joseph had done as "prime minister."
By the time his children were born, the tribes of Israel had been put into slavery. His children's names reveal a conflict in the faith of the descendants of Israel. His son Nahshon's name means "diviner," which could refer to a pagan ritual, but more positively, to a prognosticator of more modest means. His daughter Elisheba name means "My God has sworn," clearly pointing back to the covenant with Abraham to bring the people out of Egypt.
In the midst of this changing scene, Amminadab promised his Elisheba to Aaron, the brother to the banished prince Moses who had fled his privileged place some years before. Some time after this, his son Nahshon would father his grandson Salmon, one of the children under the age of 20 at the beginning of the exodus.
It is not known whether Amminadab died before the exodus. A generation older than Aaron, he would have been near a hundred years old by the time. His son Nahshon, who would become a leader of the armies of the tribe of Judah during the wilderness wanderings, would die there.
It is possible that the old man did see his grandson Salmon, who would be numbered in the second census, before he died.
Of his grandson's by Elisheba, Nadab and Elihu would foolishly flaunt God's law and die as a result of it. Eleazar and Ithamar would follow their father Aaron as priests of Yahweh. The position of high priest would be come from his grandsons and was still in place at the fall of Jerusalem in AD 70.
As the father of Elisheba and Nahshon, Amminadab was the progenitor of both the royal and priestly classes of Israel. Mary of Nazareth, as a relative of Elizabeth, was doubly his descendant. Since Elizabeth was a "daughter of Aaron," so was her relative Mary. Besides this, the line of Nathan, from David, provided the genetic link to the great king.