1 Kings 1:7

And he conferred with Joab the son of Zeruiah, and with Abiathar the priest ,.... About getting the kingdom into his hands: and they were very proper persons to consult with, who, if gained to his interest, might be of great service, the one being the general of the army, and so had a great interest in the soldiery, with whom he could make way for him, and defend him, and the other was the high priest, who might be thought to have a great share in the affections of the people, and whose office it was to anoint the king; and he might the rather apply to them, knowing them to be, on some accounts, discontented persons:

and they following Adonijah, helped him ; they took on his side; Joab knowing David's hatred of him on account of his murder of Abner and Amasa, and especially for his slaying his son Absalom, and his insolent behaviour towards him, and perhaps he might fear, or had an him of what he had charged Solomon with concerning him; and Abiathar, who saw plainly that the priesthood in Eli's family was declining, and that Zadok was the favourite priest with David, and in all probability would be with Solomon; all which might influence these two persons to join Adonijah, and who, by so doing, greatly encouraged him, and many others to flock to him, which much helped and served his cause.