We have to cope with many different situations in life; some happy, sad, troubling, worrying and even frightening.  The Christian must learn to face each situation steadily, holding on to their faith triumphantly.  We must learn to turn to Him again and again and find a hiding place in our God far from the troubling thing.
 
In the very centre of our being there is a place for God to dwell, like the eye of the storm. When we allow the troubling thing into this part of us then we have failed to keep God in the centre and Christ on the throne of our hearts.
 
We are made in the image of God and so if there is a place of quiet, deep within us, then there is a place deep in the heart of God too.  A place of utter stillness, strength and peace.  I think this verse speaks of this.
 
‘His pavilion’ is when He brings us into the safety of His presence; ‘the secret places of His tabernacle’ speak of the very core, the centre of our God; ‘the rock’ His strength.
 

“And then shall mine head be lifted up above mine enemies round about me;

therefore I will offer in His tabernacle sacrifices of joy;

I will sing, yea, I will sing praises unto the Lord.” verse 6

 
This is what we find when we remain in that deep inner place of hiding.  Our heads will be lifted up and from that place of strength we will be able to offer to God sacrifices of joy.  There we will sing.

A soul cannot sing and be joyful when it is sad, troubled, worried or even frightened so let us learn to live in the secret of His tabernacle and we will have a joyful song within us.