Mirror of the Honest Life and Eight Points of Spiritual Perfection

and do not permit [the soul] to be in peace.

Fourth, that you ought to strive at all times for purity of heart; that is, that you continuously turn into yourself as if your carnal senses were closed, and keep the hostelry of your heart diligently barred, as much as possible, from sensible forms and the images of earthly things. For purity of heart, among all spiritual exercises, is in a way the final intention and the reward of all labors which a retired soldier of Christ is accustomed to receive in this life; it claims the primacy for itself. [Keep] your affection with all diligence [free] from all these things that could impede its liberty and from all possibilities of binding and holding that affection to cling [to the world]. According to the Mosaic Law: "Let every man remain among his own, let no one go out the door of his house on the Sabbath day, and the people shall keep the Sabbath" Exodus 16:29. For to be in oneself is to gather the dispositions and affections of one's heart into one true and most simple good and to hold them gathered. But to keep the Sabbath is to have the heart absolved from carnal affection that infects it, and from worldly cares that distract it, and to rest sweetly in the peace of one's heart as if in a port of silence, in the love and fruition of one's Creator.

Above all other things, however, let your principal effort always be this: that you keep your mind always lifted upward in the contemplation of divine things, so that your mind may be regularly translated to divine things and to God. Whatever, however, is different from these—even if it seems to be the castigation of the body, fasting, or vigils—must be judged as secondary and inferior exercises of virtue, useful only insofar as they contribute to the purity of the heart. It is for this reason that very few arrive at true perfection, because they spend time and strength on means that are not very useful, and they neglect and postpone the due remedies. You, however, if you desire to arrive directly at the intended end, ought to pant without cease for the perpetual purity of the heart and tranquility of the mind, and keep your heart lifted continually to the Lord. It is true, however, that no mortal can cling to this contemplation continually...