What does the verse teach about Oved Edom?
'Rashi': Just like [David] left Asaf appointed over Shir, he left Oved Edom over the gatekeepers.
To whom does "Acheihem" apply?
Radak: [The brothers of] Oved Edom's sons, like it says below (26:8) "Hemah u'Vneihem va'Acheihem 1 ."
Malbim: [The brothers of] Oved Edom and Chosah.
Also the brothers of his sons are his sons! There, Radak explained that va'Acheihem includes sons who were not mentioned. (PF)
Here it says that there were 68. Below (26:8) it says that there were 62!
Malbim #1: Radak holds that also here discusses Oved Edom's sons and brothers. He must hold that six died in the plague 1 .
Malbim #2: Here discusses the sons and brothers of Oved Edom and Chosah. Even though Chosah had 13 sons and brothers (26:11), now he had [at most] seven.
Or, perhaps here includes Oved Edom's brothers. He said "Acheihem" applies to Oved Edom's sons, like below - this is a Chidush, for the verse did not mention them, but perhaps Acheihem applies also to Oved Edom himself. (PF)
What do we learn from "v'Oved Edom ben Yedisun v'Chosah l'Sho'arim"?
Malbim: They were the special gatekeepers.
