This is one of the most famous sermons and astrological texts written by Marsilio Ficino for Christmas 1482.
Marsilio explains the birthchart of Jesus and the role of Magi: he dismisses the theory of Great Conjunction but he can’t renounce to one of the most known texts of Middle Ages, few lines from Albumasar’s Great Introduction.
Albumasar writes ( from John of Seville)
In its first facie arises a Girl called Darostal by Teucer, and she is a pure and beautiful virgin, long haired and beautiful in her face, she has two Spikes in her hand. She is seated upon some cushions, and she is feeding a child giving him some soup in a place called Atrium. And people call this child IHESUM, that in Arab is EICE. Also rising with her a man sitting upon a throne. And arises with her the Virgo star  which is at the back of the second snake, and the head of Corvus and the head of the Lion.
But a new world was coming and soon Pico della Mirandola would start his fight against Arab silly astrological theories.
On the Magi’s star, which lead them to the Christ, King of Israel, when he was born
Marsilio Ficino, De Stella Magorum, Praedicationes (1482)
Grant us your favour, My Lord, show us this day your star, the one once you showed to the Magi. The star that led the Magi to Christ, may lead us to Christ’s mysteries.
A star shall come out of Jacob, and a Sceptre shall rise out of Israel. With these words Balaam, in the book of Numbers, foretells the coming of the Messiah. One day a star will rise in an extraordinary way in Judea. Balaam lived in the Eastern area, where Magi lived too, and among them there were some priests very skilled in astronomy, ruling people. Thus, they, attentive students of sky signs, had noticed the event that, according Balaam, would be showed by the prodigy of the star.
Eventually, when Jesus was born, an extraordinary comet shone in the highest part of the sky. What scholars thought about a comet is stated by Origen in Contra Celsum, when he refers what he read in the book of the Stoic Cheremon about the comets, that in some cases they can indicate happy and prosperous events. The one shining at the time of Augustus has this nature.
He says that Cheremon mentioned the story; and he adds that Chaldeans, after having studied and realized that their demons were weakened, left for Judea, in order to worship a god stronger than their demons. 
Calcidius the Platonist attests the same, referring us several stories about stars. We can see very rarely the ones signifying great calamities. Then, he adds, there is another tale too, more sacred and venerable (which he states it was noticed by Chaldeans too) stating that neither illness or death were heralded with the birth of a certain specific star , but the holy coming of God, in order to bring the grace of redemption to the man and to deadly things.
Therefore Chaldeans venerated the just born god, bringing him gifts. Calcidius states this. 
And Svetonius is another witness with this words: “an old and persistent opinion crossed all the East, so it was believed that in that time fate decreed some men from Judea would conquer the power, and because of this Jews clashed with Romans and lost.” 
From this we deduce that in some way Eastern astronomers, using astrology rules, and according omens consistent with them, judged that a king due to reform the world for the better, with enormous authority, should be born in that time.
In judging the comet prosperous and healthy, in fact, they recognize it comes from the nature of the Sun, Jupiter, and Venus. They teach in fact that when its colour is dark, the comet is Saturnian, and means plague and famine. When it is of the same colour of fire, it is a Martian comet, and means battles and fires, and the greatest part of comets are of these two varieties. In fact the fire and impetuous strength of Mars draws terrestrial fumes higher, in the upper part of the air, near the Fire sphere where they burn. From comets, from omens and from planets they judge about several events: from those comets that, when rising, turn from South to North encircled by their tail, and the opposite.
So, when Eastern astronomers, in December, saw a comet rising in the beginning of Sagittarius, they judged it a benevolent apparition, because it shed golden rays, being of Sun nature; silver rays because of Jupiterian nature, mixed rays because of Venusian nature.  Maybe Jupiter too was in that moment in the beginning of Sagittarius. The Sun, if we are right in calculations, was in the middle of the sign. Maybe Venus, always near to the Sun, was in the last degree of the sign: likely this is the sky configuration at Jesus birth, in the month of December, if he was born after the first half of the night. In fact we read in the Gospel that while shepherds kept their night vigils, the Angel said: this day he is born.
This celestial configuration caused great admiration and great quarrels. Because of the position of Jupiter, Sun and Venus, they judged he would be a rightful king, of greatest fame, very merciful, but because of the Sun he could not be very rich. How will he be both a great king, and poor? Considering Jupiter rising in the angle of the geniture, they judged the nativity very favorable; but sterile because of the Moon in the first facie of Virgo, being the stress on a virgin rather than a pregnant woman.
Because of these astrological considerations and because of Balaam and other prophets’ predictions, a common opinion crossed the East: a king of justice was born or appointed- because of Jupiter- of truth – because of the Sun – of grace – because of Venus; but nobody knew the place where he was born.
But the comet guided them towards two months, according the two hours of the ascension of the sign, and even if its direction was from South towards Judea, anyway it does not indicate a determined place. Till this moment, in fact they could not say if he was already born or going to be born, if he was sent by the sky or he came by divine will. But because the comet showed itself again after two years, with reference to the two months, and this time, not in higher, but in the lower levels of the sky; the Magi recognizing the comet, followed its movement and under its guidance they arrived in 41 days to Jerusalem.
They were not looking for an human king anymore but for a God king. They saw in fact that the kind of comet and its motion could not be natural. The fact that Magi arrived there, and they informed Herod of the birth of so a great king, and the moment of his arrival, can be attested not just by the Gospel, but even by Macrobius, who says: “When Augustus heard that among the children killed in Syria by Herod, king of the Jews, there was even Herod’s child exclaimed: it’s better to be Herod’ swine rather his child. “
So I believe that the comet, not natural but divine, was moved, and lighted by the Archangel Gabriel. It was Gabriel in fact that announced John, Christ’s forerunner, to Zachariah and Christ to Mary; it was him to show to the Gentiles the birth of Christ and the place where it occured; and through the Gentiles he persuaded Jews too. And under the form of a star informed the students of stars, and through the light of the star, derived from the Sun he guided them towards the Sun.
The astronomers brought gold to the just born king , because they judged him having a Sun nature; with perfumed incense they indicated the grace of Venus, with myrrh they indicated a life under the influence of Jupiter, unaware of putrefaction. In the same time these gifts are converged in another secret. In fact with the gold they helped him because he was a poor; with the myrrh they gave strength to the tender flesh; with the incense they perfumed the stable. The gave him the gold because he was a king; the incense because he was a priest, the myrrh because he was God.
It is likely the comet was an Angel; like an Angel in human guise guided Tobias travel,  in the same way the Angel under the guise of a comet guided the journey of the astrologers towards Christ.
In fact as Moses the Egyptian, the most learned of the learned Jews, states, the supreme knowledge of the stars led Abraham to understand, the first and only one in his generation, that there is a first and only cause in the sky and pleading to worship him, and because of this he had from God the gift of the grace and the prophecy. But let us come back to the Comet.
According Luke’s Gospel, in the very moment when our Christ was born, an Angel of God encircled with light shepherds and heralded them a great joy, telling them: today is born the Savior of the world.  He said correctly “today” because he intended “in this day”, even if it was the midst of the night. The light of the comet in fact brought the daylight in that moment; from this David said: and the night will shine as the day. 
Then the Angel, turned toward the East, promptly directed the comet towards Persia, in order to guide from there Magi to Christ. From here Isaiah said: Arise, shine; for thy light is come, and the glory of the Lord is risen upon thee. And people walk in your light. 
In fact when the Lord was born , this light appeared around Jerusalem. Thus, Gentile Magi walked to this light. Travelling first from the Judea to the East, and in fact the comet came back then from the East to Judea, guiding the Magi there . We believe the fact that the comet was the same Angel heralding the great joy to the shepherds, because when the Magi saw again the star, they greatly rejoiced: I said “greatly” because they already rejoiced, like shepherds did, the first time they saw it. So they rejoiced greatly because the good already experimented arriving in its plenty is greatly appreciated , and the fact one could get more of it after a stop.
The same Angel, who guided, with visible rays, Magi to Christ, warned then with invisible rays, the minds of sleeping Magi to not reach Jerusalem; and warned Joseph to fly in Egypt with the child. At the time of Christ death it was the Angel who caused a Sun eclipse in a supernatural way during a Full Moon, because it was in fact a Full Moon, and he turned at midday the day in night; him, that for the birth of Christ had turned the midnight in day. From this David said: the darkness and the light are both alike to thee;  because both are done by the same Angel, and both times in the middle hour, both of the day and the night.
In which way the Angel condensed the comet? Being directly in the middle level of the air, he put together one thousand stadia of air, spread around him, in a smallest area, he tied them to him with extraordinary power, like the body to the soul, and parted them from other elements. Then, using the energy of the clot, a lot of fluid was pushed in a very narrow space, and parted from water. But why did the Angel condense air? Because the light he was going to impress in the air could be perceived by the human eye. In fact a very rare substance always escapes to the eyesight. Where did he take the light to transmit to that body? From the light of his mind. In it in fact there is an invisible and intellectual light, which transmitted in the air, becomes visible; in the subtler air is visible to the Saints; in the denser, to the others too.
We told that Magi arrived to Jerusalem the twenty first day after the birth, when Mary, observed the time of purification, led her child to the Temple. So, in the day Simeon and Anna know Christ,  Magi preach for him in Jerusalem and still they don’t know him.
The day after they reach Bethlehem. but because Joseph, to the approaching of Magi, receives the order to fly with the child, it is unlikely he brought the child to the Temple after the divine order: it is likely that Magi had welcomed the child after the purification.
What we told about Sagittarius, because of calculation of someone’s else, could be in my opinion be told more rightly about Virgo and midnight. While Christ was born, necessarily one of the twelve signs was rising. I don’t know which sign I should give to the One is born from a Virgin, more than Virgo. And mostly the first facie of this sign. In fact every sign has three facies. In the first facie of the Virgo, like Albumasar states, Indians and Egyptians have contemplated the image of a virgin girl, very beautiful, sitting, feeding a child. The rising of this facie agrees perfectly with the child born from a Virgin, and if one well compute, the first facie of Virgo is rising in the middle of December at midnight.
People believe the comet glowed in this facie, not a cause but sign of Christ. If the comet had the power to cause a virginal delivery, surely it would do this more frequently in the centuries. But celestial bodies can’t create a religion that putting aside the sky would worship something above the sky and hope in it; celestial fate cannot benefit a law denying the fate.
Light which from Good is spread through all the spirits, is benefic. It grants us to direct towards the Good and quieten in it and makes possible we love the good and rejoice in it. Whatever particular good has with him the image of the good itself. Men without charity, the ones tormented by envy are starting to fall in the darkness, out of benefits of light. In fact they hate good and they suffer in it.
Gentile da Fabriano, Adorazione dei Magi, Firenze, Galleria degli Uffizi, 1423.
Ornella Pompeo Faracovi. Marsilio Ficino, Scritti sull’astrologia, BUR, Milano, 1999.
 Teukros in Rethorius TR “In the first facie there arises a Goddess seated upon a throne and holding a Child, whom some say is the goddess Isis in the atrium nursing Horus.”
 Being a bicorporeal sign, Virgo is often described as two women or a woman and a man.
 The star on the tip of the southern, left wing, of the nature of Mercury and Mars. But in version of Hermann it became Bethlem star, as in Fendulus illustration Liber astronomiae.
 Virgo dodekaoros.
 Numbers, 24, 17.
 Origen, Contra Celsum 1, 60
 Calcidius, Timaeus a Calcidio Traslatus Commentarioque Instructus, 126.
 Svetonius, De Vita Caesarum; 8, 4,5.
 Pseudo Ptolemy “Sulle stelle chiomate ” (On tailed stars) and C. Heingartner “Il trattato sulle comete” (Treatise on the comets) in Arcana Mundi, BUR 1995
 Luke, 2, 8-14.
 Macrobius, Saturnalia; 2, 4-11.
 Luke, 1, 10-38.
 Genesis, 15, 5.
 Luke, 2, 8-14.
 Psalms, 138, 12.
 Isaiah, 60,1.
 Jewish Pesah is 14 days after New Moon.
 Psalms 139,12.
 Luke, 2, 25-38.