Sources : Peridexion Tree

Physiologus [ca. 4th century CE]: There is a tree found in India called the peridexion tree, the fruit of which is indeed quite sweet and pleasant. The doves delight in the fruit of that tree and live in it while eating its fruit. The dragon, who is the enemy of the doves, fears the tree and its shade in which the doves dwell and is unable to approach the doves or the shade. If the tree’s shadow falls to the west, the dragon flees to the east. If, on the other hand, its shadow falls on the east, he flees to the west. If it happens that a dove is found outside the tree or its shadow and the dragon discovers it, he kills it. The Father of all is the tree and Christ the Son is the shade, just as Gabriel said to Mary, “Do not be afraid, Mary, the Holy Spirit will come upon you, and the power of the Most High will overshadow you” [Luke 1:30 and 35]. The fruit is heavenly wisdom and the dove is the Holy Spirit. Beware, O man, lest after you have received the Holy Spirit (that is, the intelligible, spiritual dove descending from heaven and remaining over you), you should be outside the divine being, a stranger to the Father, Son, and Holy Spirit, for the dragon (that is, the devil) will kill you. The devil is unable to approach the tree or the shadow or the fruit. And, if you have the Holy Spirit, the dragon (tat is, the devil) will be unable to approach you. - [Curley translation]