The Vita Sanctae Brigidae describes the monastic church at Kildare as expanded in the seventh century to accommodate the growing community. Cogitosus's phrasing 'on account of the growing number of the faithful of both sexes, a new reality is born in an age-old setting' places this reconstruction in the recent past, and the miracle which follows with the craftsman's dispute over how to fit an old door formerly used by Brigit into a doorway of the new building, has the freshness of immediate personal experience of interviews with witnesses. Indeed, the composition of Cogitosus' Vita may have been part of the same promotion of Kildare as the construction of the new church and the translatio of Brigit and Conleth into its sanctuary. If so, then the new church must be estimated to have been constructed approximately between 640 and 670.
Canon O'Hanlon recounts the details of this miracle in his Lives of the Irish Saints:
A miracle, which occurred in repairing this church, and which, Cogitosus thinks should not be passed over in silence, has been placed on record. When the old door of the left side passage, through which St. Brigid used to enter the church, had been altered, repaired, and placed on its former hinges, by artisans, it could not exactly cover the opening as required. A fourth part of this space appeared exposed, without anything left to fill it ; and, if a fourth more were added and joined to the height of the gate, then it might fill up the entire altitude of this reconstructed and lofty passage. The workmen held a consultation, about making another new and larger door to fill up this entrance, or to prepare a panel for an addition to the old door, so as to make it the required size. A principal artisan among the Irish then spoke :"On this night, we should fervently implore the Lord, before St. Brigid, that before morning she may counsel us what course we ought to pursue, in reference to this matter," After these words, he passed a whole night in prayer, beside St. Brigid's tomb. On the morning he arose. He then found, on forcing and settling the old door on its hinge, the whole passage was filled, so that a single chink was not left uncovered, nor in its height was any, even the least, excess discovered. Thus, it happened, as the whole aperture was filled, that St. Brigid—as was generally believed—had miraculously extended that door in height. Nor did any part appear open, except when the door was moved on entering her church. This miracle, accomplished by Divine omnipotence, was evidently manifested to the eyes of all, who looked upon the door and the passage.