When you see yourself, therefore, growing sluggish in prayer, take up a book and by paying careful attention to what you read absorb its meaning. Do not read through the words in a cursory fashion, but examine them with depth of understanding and treasure their meaning. Then meditate on what you have read, so that your mind in comprehending it is mellowed and it remains unforgotten.
Thus will your ardor for reflection on things divine be kindled, for ‘a fire shall be kindled during my meditation’ (Psalm 39: 3 LXX). Just as you have to chew food before you can savor its taste, so you have to ruminate in your soul on holy texts before they enrich and gladden the mind: as the Psalmist says, ‘How sweet Thy words are in my throat’ (Psalm 119:103). Learn by heart the words of the Gospels and the sayings of the blessed fathers, and study their lives diligently, so that you may meditate on these things during the night. In this way when your mind grows listless in prayer you can refresh it by reading and meditating on sacred texts and rekindle its appetite for prayer.
~Theoliptos, Metropolitan of Philadelphia
Prayerful Life 