And when he saw himself to be strengthened in his rule, he cut the throats of the servants who had killed his father, the king
Other versions
King James Version
Now it came to pass, when the kingdom was established to him, that he slew his servants that had killed the king his father. English Standard Version
And as soon as the royal power was firmly his, he killed his servants who had struck down the king his father.New International Version
After the kingdom was firmly in his control, he executed the officials who had murdered his father the king.