Küll (the universal), in the aspect of the divine wāḥidiyya (the unity that gathers all names), is a name of God Most High. For this reason, it is said: He is unique in His essence, and universal (küll) in His names and attributes. (Kāshānī, 68; Jāmiʿ, 93)
Küll, that is, everything other than Allah, in terms of manifestation, is from Him (has manifested from Him), subsists by Him, proceeds from Him, and is returned to Him. As Allah Most High has said: "Everything will be returned to Him." (al-Baqara 2:245) One who knows this also knows that if, for even the blink of an eye, the universality (külliyyet) that appears in God, like the image appearing in a mirror, were to be hidden, the world would instantly cease to exist. If the existence of the world is real through God, then its continued existence is also only possible through His protection, grace, and gaze of mercy. (Asfār, 43)