1 Chronicles 9:12
And Adaiah the son of Jeroham, the son of Pashur, the son of Malchijah, and Maasiai the son of Adiel, the son of Jahzerah, the son of Meshullam, the son of Meshillemith, the son of Immer; And Adaiah the son of Jeroham, the son of Pashur, the son of Malchijah, and Maasiai the son of Adiel, the son of Jahzerah, the son of Meshullam, the son of Meshillemith, the son of Immer;
The verse belongs to the genealogical lists in the first nine chapters of Chronicles, which record names and events with particular attention to Judah and the priesthood. It is part of the records that preserve the identities and continuity of God's people and the integrity of Israel's tribes. After the exile those genealogical records preserved hereditary descent, helping to establish land assignments and to identify those whose inherited duty was temple service.
The verse names priests and their family lines within a passage describing the division of work among the priests and others responsible for temple service. It stands in the list of 1 Chronicles 9:1-32 describing the order of service after the return from Babylon. That order was originally ordained by David and Samuel, so the Sabbath mentioned in that section relates to the events of David's life.