We know from the _Book of Armagh_ that it has been thus recited at least from the eighth century, so that even then its use was universal, and in a certain sense obligatory. St. Patrick is there declared entitled to four 'honours' in all the churches and monasteries of Erin. First, his festival was to be celebrated for three days and three nights with every kind of good cheer except flesh--that being forbidden in Lent; secondly, a special offertory was to be immolated in his honour, which seems to imply that there was a special offertory, and perhaps preface for the Mass on these days; thirdly, his Hymn--that is, the hymn in praise of Patrick written by his nephew, St. Sechnall--was to be sung during these days; and fourthly, "his Irish Canticle was to be always sung" in the liturgy, as it would seem, and apparently also throughout the entire year. So it appears that from the earliest ages this Canticle was regarded in the Irish Church as the genuine composition of St. Patrick, and the greatest efficacy was attributed to its pious recitation. IV.--SECHNALL'S HYMN OF ST. PATRICK. 'The Hymn of St. Patrick'--that is, the Hymn composed in his honour by St. Sechnall, to which reference is made in this extract from the _Book of Armagh_--is another very singular and interesting literary monument of our early Celtic Church. It has been published with valuable notes and scholia by the late Dr. Todd in the first volume of the _Liber Hymnorum_.[97] This curious Latin hymn, which is justly regarded both on internal and external evidence, as the genuine composition of St. Sechnall, or Secundinus, owed its origin to a singular circumstance. The following is Colgan's account taken from the Preface to the Hymn, as given by a very old but unknown authority:--