Keil & Delitzsch, on Neh 11:15

Of Levites, Shemaiah, a descendant of Bunni, with the members of his house; Shabbethai and Jozabad, "of the heads of the Levites over the outward business of the house of God," i.e., two heads of the Levites who had the care of the outward business of the temple, probably charged with the preservation of the building and furniture, and the office of seeing that all things necessary for the temple worship were duly delivered. The names Shabbethai and Jozabad have already occurred, Neh 8:7, as those of two Levites, and are here also personal names of heads of Levites, as the addition הלויּם מראשׁי informs us. As the office of these two is stated, so also is that of those next following in Neh 11:17; whence it appears that Shemaiah, of whom no such particular is given, was head of the Levites charged with attending on the priests at the sacrificial worship (the האלהים בּית מלאכת, Neh 11:22). The three named in Neh 11:17, Mattaniah an Asaphite, Bakbukiah, and Abda a Jeduthunite, are the chiefs of the three Levitical orders of singers. Mattaniah is called התּחלּה ראשׁ, head of the beginning, which gives no meaning; and should probably, as in the lxx and Vulgate, be read התּהלּה ראשׁ: head of the songs of praise, - he praised for who praised, i.e., sounded the Hodu for prayer; comp. Ch1 16:5, where Asaph is called the chief of the band of singers. He is followed by Bakbukiah as second, that is, leader of the second band (מאחיו משׁנה like משׁנהוּ, Ch1 16:5); and Abda the Jeduthunite, as leader of the third. All the Levites in the holy city, i.e., all who dwelt in Jerusalem, amounted to two hundred and eighty-four individuals or fathers of families. The number refers only to the three classes named Neh 11:15-17. For the gatekeepers are separately numbered in Neh 11:19 as one hundred and seventy-two, of the families of Akkub and Talmon.