And, behold, after a little I see an array of many men coming, and in the midst of them one man of so remarkable a size as to overtop the tower. And the six men who had worked upon the building were with him, and many other honourable men were around him. And the virgins who kept the tower ran forward and kissed him, and began to walk near him around the tower. And that man examined the building carefully, feeling every stone separately; and holding a rod in his hand, he struck every stone in the building three times.
And when he struck them, some of them became black as soot, and some appeared as if covered with scabs, and some cracked, and some mutilated, and some neither white nor black, and some rough and not in keeping with the other stones, and some having [very many] stains: such were the varieties of decayed stones that were found in the building. He ordered all these to be taken out of the tower, and to be laid down beside it, and other stones to be brought and put in their stead. [And the builders asked him from what mountain he wished them to be brought and put in their place.] And he did not command them to be brought from the mountains, [but he bade them be brought from a certain plain which was near at hand.] And the plain was dug up, and shining rectangular stones were found, and some also of a round shape; and all the stones which were in that plain were brought, and carried through the gate by the virgins.
And the rectangular stones were hewn, and put in place of those that were taken away; but the rounded stones were not put into the building, because they were hard to hew, and appeared to yield slowly to the chisel; they were deposited, however, beside the tower, as if intended to be hewn and used in the building, for they were exceedingly brilliant.
Source: The Pastor (or "The Shepherd") (New Advent)