A heart that would contemplate must be bright as a mirror, shimmer like some still stretch of water crystal clear, so that in it and through it the mind may see itself, as in and through a mirror, an image in the image of God. The heart that covets the sight of God as in a mirror must keep itself free from cares, from harmful, unnecessary and even necessary ones. It must keep itself ever alert through reading, meditation and prayer. “Blessed are the pure of heart; they shall see God.” (Mt 5:8)
–Blessed Isaac of Stella (Twelfth Century)