They only consult to cast him down from his excellency: they delight in lies: they bless with their mouth, but they curse inwardly. Selah. To cast him down from his excellency - They are consulting to dethrone me, and use treachery and falsehood in order to bring it about: "They delight in lies."
They bless with their mouth - Probably alluding to Absalom's blandishments of the people. He flattered them in order to get the sovereign rule. Or it may refer to the people of Jerusalem, whose perfidy he saw, while they were full of professions of loyalty, etc.; but he could not trust them, and therefore retired from Jerusalem.