But the king shall rejoice in God; every one that sweareth by him shall glory: but the mouth of them that speak lies shall be stopped.
But the king shall rejoice in God. It is that he is God's anointed king which forms the ground of his hope. Therefore he says "the king" instead of I.
Every one that sweareth by him - i:e., by the king, as the token of loyalty (Genesis 42:15-16). Shall glory - shall triumph in the success vouchsafed by God to the king's cause.
But the mouth of them that speak lies - the rebels (Psalms 62:4).
Shall be stopped - silenced in death (Psalms 63:9-10).