Komentarz do Diwrej ha-jamim I 7:12

And Shuppim and Huppim, the sons of Ir, Hushim, the sons of Aher Ezra, who wrote this book of genealogy, did not know whether they were of the sons of Benjamin or not. He therefore listed them alone. He was also in doubt because it is written: “And Machir took a wife of Huppim.”