The Daas Zekeinim explains the reason that the Torah emphasizes Betazlel’s grandfather, Chur, while it does not trace Ahaliav’s lineage to his grandfather. Chur was killed as a consequence of his role in the Golden Calf. The Mishkan served as a source of atonement for the sin of the Golden Calf. Therefore, the Torah determined that Betzalel, the unique individual designated as the prime builder of the Mishkan, should have his yichus, ancestry, delineated. His ancestry is traced to the individual whose martyred death is atoned by the Mishkan.
This exposition is enigmatic. What relationship is there between Chur’s death and the building of the Mishkan? Why should his name be stressed more than anyone else’s? We suggest that Chur’s death played an integral role in the building of the Mishkan. Why was Betzalel really chosen for this exalted position? Certainly, he was a gifted and dedicated person, who was willing to be moser nefesh, to sacrifice himself, for he building of the Mishkan. Was he the only one in Klal Yisrael, however, who deserved this distinction? In what realm is his uniqueness found?
We suggest that Betzalel’s ancestry was the motivating factor in his spiritual ascendancy. He was the grandson of Chur, who gave up his life to uphold the sanctity of Torah! He would permit neither any change in Torah transmission nor any incursion against its leadership building a Mishkan in which Hashem’s Shechinah would repose. He was willing to devote himself with mesiras nefesh, self-sacrifice, to perfection, so that every aspect of the Mishkan be exactly as deemed by the dvar Hashem, word of Hashem. Betzalel’s blood was infused with this exemplary devotion. His heritage was replete with this sublime dedication. Indeed, the building of the Mishkan actually commenced with Chur’s death.
