The light of certainty (yaqīn) entrusted to the hearts of the gnostics (ʿārif) always receives aid and illumination from the sun of reality that manifests from the treasures of the unseen (ghayb).
Poetic Translation
The radiant full moon entrusted within the heart of the gnostic (ʿārif)
Is ever illumined by the sun of the treasure of the unseen (ghayb)
Explanation
What is meant by the treasures of the unseen (ghayb) are the eternal, Divine attributes. For the qualities of the ʿārif-billāh (one who knows God) are derived from Divine attributes, and his characteristics from Lordly (Rabbānī) characteristics. When Allah manifests to the group of ʿārifūn (gnostics) with His eternal Divine attributes, just as the bright moon constantly benefits from the ever-shining sun, so too does the light of the ʿārif's heart continually seek aid from the lights of the eternal attributes.
Sometimes, just as an eclipse of the moon occurs when the shadow of the earth comes between the sun and the moon, so too can the imaginings of the nafs (the lower self) and natural impulses come between the heart of the ʿārif and the manifestations of the Lordly attributes, casting a shadow and preventing benefit from the lights. Thus, an eclipse may occur in the light of certainty (yaqīn) entrusted to the hearts of the ʿārifūn, and the state experienced at such times is termed the state of constriction (qabḍ). For the heart's abode to always receive the light of effusion and manifestation is a consoling proof of the successive Divine grace. Thus, the people of reality have said: "When Allah befriends a walī (friend of God) endowed with karāma (a saintly wonder), He protects his luminous heart from all others and makes it ever the locus of Divine lights!"