“The first piece of this class (adopting the chronological order) is the prayer of St. _Aireran_ the Wise (often called _Aileran_, _Eleran_, and _Airenan_), who was a classical professor in the great school of Clonard, and died of the plague in the year 664. St. Aireran’s prayer or litany is addressed, respectively, to God the Father, to God the Son, and to God the Holy Spirit, invoking them for mercy by various titles indicative of their power, glory, and attributes. The prayer consists of five invocations to the Father, eighteen invocations to the Son, and five to the Holy Spirit; and commences in Latin thus: ‘O Deus Pater, Omnipotens Deus, exerci misericordiam nobis’. This is followed by the same Invocation in the Gaedhlic; and the petitions to the end are continued in the same language. The invocation of the Son begins thus: ‘Have mercy on us, O Almighty God! O Jesus Christ! O Son Of the living God! O Son, born twice! O only born of God the Father’. The petition to the Holy Spirit begins: ‘Have mercy on us, O Almighty God! O Holy Spirit! O Spirit the noblest of all spirits!’ (See original in APPENDIX, No. CXX.) “When I first discovered this prayer in the _Leabhar Buidhe Lecain_ (or Yellow Book of _Lecain_), in the library of Trinity College, many years ago, I had no means of ascertaining or fixing its date; but in my subsequent readings in the same library, for my collection of ancient glossaries, I met the word _Oirchis_ set down with explanation and illustration, as follows: “ ‘_Oirchis_, id est, Mercy; as it is said in the prayers of Arinan the Wise’:—Have mercy on us, O God the Father Almighty!” See original in APPENDIX, No. CXXI. “I think it is unnecessary to say more on the identity of the author of this prayer with the distinguished _Aireran_ of Clonard. Nor is this the only specimen of his devout works that has come down to us. Fleming, in his Collecta Sacra, has published a fragment of a Latin tract discovered in the ancient monastery of St. Gall in Switzerland, which is entitled ‘The Mystical Interpretation of the Ancestry of our Lord Jesus Christ’. A perfect copy of this curious tract, and one of high antiquity, has, I believe, been lately discovered on the continent. “There was another _Airenan_, also called ‘the wise’, who was abbot of _Tamhlacht_ [Tallaght] in the latter part of the ninth century; but he has not been distinguished as an author, as far as we know”. It seems to us that there are three things specially worthy of our consideration in this beautiful prayer.