I heard that Dhū al-Nūn said: The essence of speech revolves around these four things: loving Allah, not loving what is little (the world), following the Qur'an, and fearing change (for the worse) in iman (faith) and action. (Qushayri, 9)
When, in the heart (qalb) of the sālik (spiritual traveler), the effects of the necessary sciences are obtained from the effusion of the universal spirit (rūḥ), we express this as kalām (speech), qawl (utterance), and khuṭāb (address). When Allah creates it with this attribute, He appoints its abode as the brain. This is so that it may govern all corners of the realm of the (bodily) kingdom, be near to the treasures of imagination (ḥayāl), thought, and memory—like a water reservoir in the desert—and so that it may be close enough to keep it in view in all its affairs. (Tadbīrāt, 160)
Kalām, derived from kalm meaning 'to wound', is a nafsī (pertaining to the nafs, the lower self) attribute of the rahmānī (merciful, divine) effects upon the sāḥib (possessor). Thus, just as a wound affects the wounded, we call these effects sāḥib. In this ḥāl (spiritual state), the first word that reaches the ears of creation is the word 'Kun' ("Be") (101). The world has only manifested from the attribute of kalām. The attribute of kalām is the turning of the breath of the Rahmān (the Merciful) toward manifestation, and in that breath, the intended individuality is disclosed. This process and what is brought into being by this breath is called kalām. For example, when someone wants to utter a letter, their breath reaches the letter—kalām al-awliyāʾ (the speech of the saints)—and the breath called 'sound' emerges. Whatever the intention is—especially if it is the letter itself, for example, from the articulation point of the letter 'ḥā' to that of 'wāw'—the intended letter emerges. This is called the stages of takwīn (creation), from which the rahmānī breath ascends. Whichever of the aʿyān al-thābita (the immutable entities, the realm in which all forms of the knowledge of the universe are fixed) is determined by existence, the speaker must have an effect upon the breath of the word (kalima) accordingly. However, the speech may be divine (ilāhī), lordly (rabbānī), or merciful (rahmānī).
If, at the moment of utterance, the speech is rabbānī or rahmānī and manifests in a different way—for example, if one says to Zayd, "Rise!"—the speaker has uttered the word 'rise'. If Zayd rises by his command, the one who commands has manifested the form of the word 'rise' in Zayd. This is ilāhī (divine), for only Allah brings about the aʿyān (entities). This applies to all creation. If the word is not heard and the effect of the command is not felt by the one addressed, then, since the himmah (spiritual resolve) is lacking, it is not ilāhī, but may be rabbānī or rahmānī. For the rabbānī and rahmānī, it suffices that the speech is brought into being. (Futūḥāt, II, 178)
kalām al-awliyāʾ (the speech of the saints) resembles the speech of the prophets. Therefore, it should be listened to, memorized, and acted upon just as the words of the prophets. A person, to the extent that he draws secrets of knowledge and gnosis from such a Muhammadan heir and perfect mujaddid murshid (spiritual guide), follows in the footsteps of the good gnostics and the select, perfect murshids. (Bughyat, 8)