Nobody detests a happy worker.
A little smile at work can make a lot of difference.
The door never closes against a happy worker.
A frowned face is a suspected face.
Happiness gives you the ability to stand in the king’s palace. Daniel 1:4.
The palace is inaccessible without a happy face.
Kings take delight in workers that make them happy.
A little smile from his worker can ease his tension and relax his environment.
That is what David did to retain his position before King Saul.