"Approaching therefore, do not come forward with the palms of the hands outstretched nor with the fingers apart, but making the left [hand] a throne for the right since this hand is about to receive the King. Making the palm hollow, receive the Body of Christ, adding ‘Amen’. …
-Saint Cyril of Jerusalem
4th Century Father and Doctor of the Church
From “Rethinking Communion in the Hand” by Jude Huntz:
A more rigorous study of the available evidence from Church History and from the writings of the Fathers does not support the assertion that Communion in the hand was a universal practice which was gradually supplanted and eventually replaced by the practice of Communion on the tongue.
Rather, the facts seem to point to a different conclusion.
Pope St. Leo the Great (440-461), already in the fifth century, is an early witness of the traditional practice. In his comments on the sixth chapter of the Gospel of John, he speaks of Communion in the mouth as the current usage: "One receives in the mouth what one believes by faith."2 The Pope does not speak as if he were introducing a novelty, but as if this were a well-established fact.
A century and a half later, but still three centuries before the practice (according to the popular account reviewed above) was supposedly introduced, Pope St. Gregory the Great (590-604) is another witness. In his dialogues (Roman 3, c. 3) he relates how Pope St. Agapito performed a miracle during the Mass, after having placed the Body of the Lord into someone’s mouth. We are also told by John the Deacon of this Pope’s manner of giving Holy Communion.
These witnesses are from the fifth and the sixth centuries. How can one reasonably say that Communion in the hand continued as the official practice until the tenth century? How can one claim that giving Communion on the tongue is a medieval invention?
…So St. Basil (330-379) says clearly that to receive Communion by one’s own hand is only permitted in times of persecution or, as was the case with monks in the desert, when no deacon or priest was available to give it. “It is not necessary to show that it does not constitute a grave fault for a person to communicate with his own hand in a time of persecution when there is no priest or deacon” (Letter 93, my emphasis). The text implies that to receive in the hand under other circumstances, outside of persecution, would be a grave fault.3 The saint based his opinion on the custom of the solitary monks, who reserved the Blessed Sacrament in their dwellings, and, in the absence of the priest or deacon, gave themselves Communion.
In his article on “Communion” in the Dictionaire d’Archeologie Chretienne, LeClerq declares that the peace of Constantine was bringing the practice of Communion in the hand to an end. This reaffirms for us the reasoning of St. Basil that it was persecution that created the alternative of either receiving by hand or not receiving at all.
…Thus the Council of Rouen, which met in 650, says, “Do not put the Eucharist in the hands of any layman or laywomen but only in their mouths.”
…Of course, the promoters of “Communion in the hand” generally make little mention of the evidence we have brought forward. They do, however, make constant use of the text attributed to St. Cyril of Jerusalem, who lived in the fourth century at the same time as St. Basil.
Henri LeClerq summarized things as follows: “Saint Cyril of Jerusalem recommended to the faithful that on presenting themselves to receive Communion, they should have the right hand extended, with their fingers together, supported by the left hand, and with the palm a little bit concave; and at the moment in which the Body of Christ was deposited in the hand, the communicant would say: Amen.”
There is more to this text than just the above, however. It also goes on to propose the following: “Sanctify your eyes with contact with the Holy Body . . . . When your lips are still wet, touch your hand to your lips, and then pass you hand over your eyes, your forehead and your other senses, to sanctify them.” This rather odd (or even superstitious? Irreverent?) recommendation has caused scholars to question the authenticity of this text. Some think that perhaps there has been an interpolation, or that it is really the saint’s successor who wrote it.
It is not impossible that the text is really the work of the Patriarch John, who succeeded Cyril in Jerusalem. But this John was of suspect orthodoxy. This we know from the correspondence of St. Epiphanius, St. Jerome, and St. Augustine. So, in favor of Communion in the hand we have a text of dubious origin and questionable content. And on the other hand, we have reliable witnesses, including two great popes, that placing the Sacred Host in the mouth of the communicant was already common and unremarkable in at least the fifth century.
catholic-pages.com/mass/inhand.asp