2 Kings 14:5

And it came to pass, as soon as the kingdom was confirmed in his hand, that he slew his servants which And it came to pass, as soon as the kingdom was confirmed in his hand, that he slew his servants which had slain the king his father.

As soon as the kingdom was confirmed in his hand. This is regarded as implying that Judah had become a tributary dependency of Assyria, and that each prince, at his accession, required to be formally confirmed in his kingdom by his Assyrian suzerain. It was an act of justice, no less than of filial piety, to avenge the murder of his father; but it is evident that the two assassins must have possessed considerable weight and influence, as the king was obliged to retain them in his service, and durst not, for fear of their friends and supporters, institute proceedings against them until his power had been fully consolidated.