Al-Zumar (The Crowds) Sura 39: Verse 9
"Is one who does devotions throughout the night, prostrating himself and standing, cautious about the next world and hoping for the mercy of his Lord? Say: 'Are they equal, those who know and those who know not?'"
"Devotion" is undertaking the courteous acts of service outwardly and inwardly without slackening or shortcoming, being cautious because of the threatened chastisement and hoping for the promised reward.
This is the attribute of a group who are constantly at God's threshold in the station of service. Their makeup at the time of prayer becomes entirely reverence itself, and they are always burning in remorse because of shame for sin. One of the great ones of the religion said, "You must show reverence for God's commands, for it is not apparent which command brings proximity to God. You must avoid all prohibited things, for it is not apparent which prohibition brings distance from God."
It has been said that putting God's commands into practice is of two sorts, one according to the property of servanthood, the other according to the property of love. The property of love is higher than the property of servanthood, because the lover's constant wish is for the Friend to command a service. Hence his service is all voluntary and nothing of it is coerced. He acknowledges the favours done to him, and he never lays favours on God, nor does he look for recompense.
In contrast, a service that is done because of servanthood has both free choice and coercion. The person is seeking a reward and expecting recompense.
The latter is the station of the worshipers and the common faithful, and the former is the attribute of the recognizers and the sincerely truthful. The two groups can never be equal. The worshipers are satisfied with the blessings and held back from the Beneficent, but the recognizers have reached the Presence and take ease in contemplating the Friend.
Say: "Are they equal, those who know and those who know not?" Knowledge is three: reported knowledge, inspired knowledge, and knowledge of the Unseen. Reported knowledge is heard by ears, inspired knowledge is heard by hearts, and knowledge of the Unseen is heard by spirits. Reported knowledge comes to outwardness so that the tongue may speak of it, inspired knowledge comes to the heart so that explication may speak of it, and knowledge of the Unseen comes to the spirit so that the present moment may speak of it. Reported knowledge comes from narration, inspired knowledge comes from guidance, and knowledge of the Unseen comes from solicitude.
Concerning reported knowledge, He said, "Know that there is no god but God" [47:19]. Concerning inspired knowledge, He said, "Surely those who were given knowledge before it" [17:107]. Concerning knowledge of the Unseen, He said, "We taught him knowledge from Us" [18:65].
Beyond all these is a knowledge never reached by the Adamite's imagination or grasped by his understanding. It is God's knowledge of Himself in keeping with His reality. God says, "They encompass Him not in knowledge" [20:110].
"Kashf al-Asrar wa Uddat al-Abrar" - Rashid al-Din Maybudi. pp. 432, 433