St. Isaac the Syrian: "The Lord is found hidden within the commandments..."

Jesus Christ "The Land of the Living", mosaic from the Chora Monastery, Constantinople (source)

 
The Lord is found hidden within the commandments which He Himself gave, and is revealed to those who seek Him. For exactly like a sensible home is to the clean air, so the rational mind corresponds to the divine grace. For the more material you remove from the dwelling place, the more it is filled with clean air. And on the contrary, the more material that is placed in the dwelling place, the more the clean air departs. By the words "materials of the house", we think of containers and goods, and by the words "materials of the nous", we think of vainglory and pleasure. Therefore, the more one removes vainglory and pleasure, the more our heart is filled with the grace of the Holy Spirit with the working of His commandments.
-St. Isaac the Syrian

(amateur translation of text from here)

Through the prayers of our Holy Fathers, Lord Jesus Christ our God, have mercy on us and save us! Amen!