Francis X. Gumerlock has an article in Antiphon 10:2 (2006), the journal of the Society for Catholic Liturgy, entitled, "The Interpretation of Tongues in the Middle Ages."
Dr. Gumerlock points out that the Medievals interpreted the gift of tongues as found in I Corinthians 12:10 ("to another is given interpretation of tongues") in a manner very different from that of today.
After examining eight commentaries from the Middle Ages, including those of Saint Thomas Aquinas and Peter Lombard, Dr. Gumerlock finds two primary interpretations of this passage, the first being the ability to translate and the second being the ability to teach clearly.
In regards to the first interpretation, he says:
These medieval authors do not suggest that possession of the gift necessarily entails the ability to translate ancient or foreign languages by means of a miraculous, pentecostal experience, a supernatural gift of understanding another language without any previous study or natural process of learning. Not that these medieval Christian authors totally discount such a pentecostal phenomenon. They accept, for example, that this was indeed the means by which the apostles received the gift of tongues on the day of Pentecost. They also concede that God continues to display such miracles in special circumstances, such as the experience of outstanding Christian missionaries; for, according to certain hagiographical sources, preaching evangelists like St Dominic Guzman (d. 1221) and St Anthony of Padua (d. 1231) received the gift of tongues in this manner. Nevertheless, by citing Jerome as an example of a person possessing the gift of interpretation of tongues, medieval writers imply that the usual means of coming into possession of the gift is through study or time spent abroad... This more natural process is in keeping with the medieval understanding of the gifts of the Holy Spirit. The supernatural source of the gift is affirmed, but the gift is not given or used in such a way that nature is violated in the process. For medieval believers, then, grace was construed more as divine power that heals, equips, and strengthens, rather than something that supercedes nature (161-162).Remember, grace builds on nature.
But what of the second interpretation. Dr. Gumerlock notes:
In the Middle Ages, the gift of interpretation of tongues was a gift of teaching and preaching that functioned in a variety of settings. The most obvious of these settings would have been the liturgies of daily, weekly, and festal Masses and religious services associated with the sacraments. Opportunity for expression of this gift would also have been afforded at gatherings in monastic settings such as chapters, where Scripture was read and explained. The gift might also be put to use in educational settings, during morning lectures and afternoon disputations. Interpretation of tongues would also have been operational in the writing of commentaries and treatises interpreting Scripture, especially the "hard sayings" or more difficult passages of the Bible (163-164).The difference in the interpretation of this passage by the Medievals in comparison to many of the Moderns is quite striking.
Some today might criticize the Medievals for not believing in the power of the gifts that the Holy Spirit provides, but Dr. Gumerlock corrects this. "[M]edieval Christians maintained that God was still pouring out the gift of interpretation of tongues," he says, "but they witnessed this gift functioning in their time through translators and biblical expositors" (166).
With this in mind I grew curious as to what some of the Church Fathers said about this passage, so I turned to the ever-useful Ancient Christian Commentary on Scripture (New Testament vol. VII) which, sadly, in this case was not very helpful. But this situation is one that Dr. Gumerlock also addresses.
Part of the difference of interpretation of this passage then and now he suggests (at least in the English speaking world) is because many of the early commentaries have not yet been translated into English, for which reason we are in great need of the gift of interpretation of tongues.