1 Kings 1:32 (ESV)

32 King David said, “Call to me Zadok the priest, Nathan the prophet, and Benaiah the son of Jehoiada.” So they came before the king.

After David spoke to Bathsheba alone, he called to his presence three of the most important men in the kingdom, Zadok, who was the high priest, Nathan the prophet, and Benaiah, who was the commander of David’s military escort. It is to be noted that they were three of the men who were omitted from Adonijah’s guest list.

The fact that David still exercised the authority of the monarch was shown in the fact that the three men summoned came as they were called. It is possible that Nathan had anticipated the men who would be summoned.