Ps 21

Again, to the chief musician, the psalm of David.

The king shall joy in thy strength, O LORD; and in thy salvation how greatly shall he rejoice! Thou hast given him his heart's desire, and you have not withheld the requests of his lips (Psa 21:1-2).

Now the Selah indicates, really, sort of a change of thought. It sort of introduces a new idea. It is just sort of a rest, and then introducing of a new idea, new thought pattern.

For you prevent him with the blessings of goodness: you set a crown of pure gold on his head. He asks for life from thee, and you gave it to him, even the length of days for ever and ever. His glory is great in thy salvation (Psa 21:3-5):

He is talking about the king's delight in the Lord, and how he was just so gracious for what God has done.

For thou hast made him most blessed for ever: thou hast made him exceeding glad with thy countenance. For the king trusts in the LORD, and through the mercy of the Most High he shall not be moved. Your hand shall find out all your enemies: your right hand shall find out those that hate thee.

You will make them as a fiery oven in the time of thine anger: the LORD will swallow them up in his wrath, and the fire shall devour them. Their fruit will you destroy from the earth, and their seed from among the children of men. For they intended evil against thee: they imagined mischievous devices, that they are not able to perform. Therefore thou shalt make them to turn their back, when thou shalt make ready your arrows upon thy strings against the face of them. Be thou exalted, LORD, in your own strength: so will we sing of thy praise and thy power (Psa 21:5-13).