Chapter 174
On the Same Topic
That novice who wrote the Jesus Prayer on his heart clearly placed all the power of prayer in the words. Let him acquire the habit of walking in the presence of God and perform every duty of obedience in the best manner, knowing that the Lord is watching him and for good fulfillment of obedience is preparing a reward for him, while for carelessness (“just to get it done”) – either nothing, or something punitive. In this way he will become accustomed to praying mindfully and with attention.
(Letter 929, vol. 5, pp. 215–216)