There is no mixture within Light, for Light is pure, noble and praiseworthy.
If ones focus is upon anything other than Light, then one finds a mixture, and every mixture contains impurities.
“And now, dear brothers and sisters, one final thing. Fix your thoughts on what is true, and honorable, and right, and pure, and lovely, and admirable. Think about things that are excellent and worthy of praise.”
The One who is Light spoke;
“Let there be Light…”