Matthew Poole and continuators on 1 Chronicles 25:3

3 Of Jeduthun: the sons of Jeduthun ; Gedaliah, and Zeri, and Jeshajah, Hashabiah, and Mattithiah, six, under the hands of their father Jeduthun, who prophesied with a harp to give thanks and to praise the LORD.

Or, his sons, (the construct Form being used before the absolute, of which there are Examples in Scripture) Ieduthun, called by his Fathers Name: Otherwise they are not six; unless either Ieduthun their Father be included in that Number: or Shimei mentioned v. 17. be one of them, as many Learned Men think. See the like, 1 Chron. 24. 23.

Marginal references: Or, Izri, ver. 11.; with Shimei mentioned ver. 17.