Chief of the fathers. — Heads of the father- houses. They were the heads of the chief divisions in each sub-group of the tribe.
Sanctify yourselves. — Special purifications appear to have been prescribed in connection with all sacrifice and worship. (Comp. Genesis 35:2; Exodus 19:10; Exodus 19:15; Exodus 30:17-21.) Bathing the person, and washing or changing the garments, and keeping oneself aloof from whatever was regarded as defiling, were the main requisites. And all this was needful to teach Israel that the All-pure requires purity in His worshippers. (Comp. 2 Chronicles 30:3.)
The ark of the Lord (Jehovah) God of Israel. — Contrast the simpler expression, “ark of God” (1 Chronicles 13 and 1 Chronicles 14:1-2). Here David uses a specially solemn title, by way of warning. Further, the term “God of Israel” suggests that the undertaking is national, and that the nation’s future welfare depends on its due performance (1 Samuel 2:30). Israel’s vocation was to be “a kingdom of priests, and an holy nation” (Exodus 19:6), as the chronicler has well understood.
Unto the place that I have prepared for it. — Unto (that) I have prepared for it. The relative is omitted. (Comp. 1 Chronicles 29:3 and 2 Chronicles 1:4.)