Kabz (constriction) and bast (expansion) are, according to the people of maʿrifa (gnosis, experiential knowledge of God), two noble ḥāl (spiritual states). When the True (God) subjects them to kabz, He makes them reserved with respect to permissible things such as livelihood, eating, drinking, and speaking. When He grants them the expansion of kabz-bast, He returns these things to them and undertakes to protect them in this regard. Accordingly, kabz is the ḥāl of the ʿārif (the one endowed with maʿrifa); in it, he has no merit other than his maʿrifa. Bast is the ḥāl of the ʿārif as well. The True grants him this state so that people may be refined by him, and He takes him under His protection. (Lumaʿ, 419)
Regarding the meaning of kabz and bast, Junayd (may God have mercy on him) said (by relating them to khawf and rajāʾ): "Rajāʾ (hope) expands (bast) the heart by opening it, while khawf (fear) constricts (kabz) it by causing anxiety over sin." (Lumaʿ, 420)
Kabz and bast are two states that the servant attains after passing through the maqām (spiritual stations) of khawf (fear) and rajāʾ (hope). The khawf of a murīd (aspirant, disciple) newly entering Sufism corresponds to the kabz of the ʿārif, and his rajāʾ corresponds to the bast of the ʿārif. The difference between kabz and khawf, and between bast and rajāʾ, is as follows: khawf relates to a matter concerning the future. That is, it arises from the anxiety of losing something desired in the future or being exposed to an undesirable situation. The same applies to rajāʾ: it is called rajāʾ when it is hope regarding the attainment of something desired in the future, or the removal of something feared, or the ending of an unpleasant situation. Kabz, however, is related not to the future but to a meaning that occurs at the present moment. Bast is likewise.
While the possessor of khawf and rajāʾ is in these two ḥāl, his qalb (the heart) is occupied with the future. The possessor of kabz and bast, however, is a captive of his moment due to the wārid (spiritual influx) that dominates and rules him at that time. Moreover, depending on the differences in the states of the Sufis, the characteristics of those in the state of kabz and bast also vary. For example,