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]

Guillaume le Clerc [ca. 1210 CE] (Bestiaire, Chapter 36): A tree there is in India the great / Beautiful and full of leaf and shady, / Fruit it bears good and sweet and choice, / And I can well assure you / As the writing apprises me, / That great is the shade which it gives. / Beautiful it is within and around / And they say it has the name / Paradixion in greek. / That sounds the equivalent in french / Of saying “environ la destre”. / Beneath this tree ’tis very nice to be; / In it there stay and dwell / Doves in great enjoyment, / For they are sated with the fruit / And rest beneath the shadow. / From there indeed they need not stir, / For they have all that they need. / There is a dragon in that country / Which to the doves is enemy, / For he eats and devours them. / But that which dwells under the tree / And within the shadow continually stays / Has nothing to doubt or fear. / The doves who know quite well / That he hates them above all things, / Keep ever under the tree, / Unless there be one foolish and silly. / Which of them stupidly goes out, / When it has gone, it repents fully. / The doves fear the dragon, / And contrariwise the dragon fears / To approach the tree and its shadow. / At no time does he hurt the doves / If he does not find them outside the shadow; / If he so finds them, they are lost. / For he is always on the watch. / When this tree casts its shadow / On the side towards the right / Then is the dragon on the left. / When the shadow turns toward the left / The dragon returns to the right. / He could not endure the shadow, / Which in its course is never doomed to die. / The doves which are knowing and wise, / Keep ever beneath the shadow / Of the tree so that their enemy / Cannot do them any harm; / But if any one foolishly goes out, / He catches it as he can do. / At once he has devoured it, / For he finds it very savoury. - [Druce translation]