A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
1 Chronicles 16:2
ch1 16:2DAVID'S FESTIVAL SACRIFICE AND LIBERALITY TO THE PEOPLE. (Ch1 16:1-6)
he blessed the people in the name of the Lord--The king commended their zeal, supplicated the divine blessing upon them, and ordered the remains of the thank offerings which had been profusely sacrificed during the procession, to be distributed in certain proportions to every individual, that the ceremonial might terminate with appropriate festivities (Deu 12:7).
1 Chronicles 16:3
ch1 16:3flagon of wine--The two latter words are a supplement by our translators, and the former is, in other versions, rendered not a "flagon," but a "cake," a confection, as the Septuagint renders it, made of flour and honey.
1 Chronicles 16:4
ch1 16:4he appointed certain of the Levites to minister before the ark of the Lord--No sooner was the ark deposited in its tent than the Levites, who were to officiate in the choirs before it, entered upon their duties. A select number of the musicians were chosen for the service from the list (Ch1 15:19-21) of those who had taken a prominent part in the recent procession. The same arrangement was to be observed in their duties, now that the ark again was stationary; Asaph, with his associates, composing the first or principal company, played with cymbals; Zechariah and his colleagues, with whom were conjoined Jeiel and Obed-edom, forming the second company, used harps and similar instruments.
1 Chronicles 16:5
ch1 16:5Jeiel--the same as Aziel (Ch1 15:20).
1 Chronicles 16:6
ch1 16:6Benaiah also and Jahaziel--The name of the former is mentioned among the priests (Ch1 15:24), but not the latter. The office assigned to them was that of blowing trumpets at regular intervals before the ark and in the tabernacle.
1 Chronicles 16:7
ch1 16:7HIS PSALM OF THANKSGIVING. (1Ch. 16:7-43)
Then on that day David delivered first this psalm--Among the other preparations for this solemn inauguration, the royal bard had composed a special hymn for the occasion. Doubtless it had been previously in the hands of Asaph and his assistants, but it was now publicly committed to them as they entered for the first time on the performance of their sacred duties. It occupies the greater part of this chapter (1Ch. 16:8-36), and seems to have been compiled from other psalms of David, previously known to the Israelites, as the whole of it will be found, with very slight variations, in Psa 96:1-13; Psa 105:1-15; Psa 106:47-48. In the form, however, in which it is given by the sacred historian, it seems to have been the first psalm given for use in the tabernacle service. Abounding, as it does, with the liveliest ascriptions of praise to God for the revelation of His glorious character and the display of His marvellous works and containing, as it does, so many pointed allusions to the origin, privileges, and peculiar destiny of the chosen people, it was admirably calculated to animate the devotions and call forth the gratitude of the assembled multitude.
1 Chronicles 16:36
ch1 16:36all the people said, Amen--(Compare Psa 72:19-20; Psa 106:48). In the former, the author of the doxology utters the "amen" himself, while in the latter the people are exhorted to say "amen." This may arise from the fact that the latter psalm originally concluded with the injunction to say "amen." But in this historical account of the festival, it was necessary to relate that the people obeyed this injunction on the occasion referred to, and therefore the words "let them praise," were altered into "and they praised" [BERTHEAU].
1 Chronicles 16:37
ch1 16:37So he left there before the ark of the covenant of the Lord Asaph and his brethren, &c.--The sequel of the chapter describes the appointment of the sacred musicians and their respective duties.
1 Chronicles 16:38
ch1 16:38Obed-edom with their brethren--Hosah, mentioned at the close of the verse, and a great number besides (see on Ch1 26:1).
to be porters--doorkeepers.
1 Chronicles 16:39
ch1 16:39And Zadok . . . before the tabernacle . . . at Gibeon--While the above-mentioned officers under the superintendence of Abiathar, were appointed to officiate in Jerusalem, whither the ark had been brought, Zadok and the priests subordinate to him were stationed at Gibeon to perform the sacred service before the ancient tabernacle which still remained there.
1 Chronicles 16:40
ch1 16:40continually morning and evening--as the law enjoined (Exo 29:38; Num 28:3, Num 28:6).
and do according to all that is written in the law--(See Num. 28:1-31). Thus, in the time of David, the worship was performed at two places, where the sacred things that had been transmitted from the age of Moses were preserved. Before the Ark in Jerusalem, Asaph and his brethren officiated as singers, Obed-edom and Hosah served as doorkeepers, and Benaiah and Jahaziel blew the trumpets. While at the tabernacle and burnt offering in Gibeon, Heman and Jeduthun presided over the sacred music, the sons of Jeduthun were door keepers, and Zadok, with his suite of attendant priests, offered the sacrifices.