This is quoted three times in the Homilies as a saying of our Lord, viz., here and in Homily III. chap. 50, and Homily XVIII. chap. 20. It is probably taken from one of the apocryphal Gospels. In Homily XVIII. chap. 20 the meaning is shown to be, that as it is the part of a money-changer to distinguish spurious coins from genuine, so it is part of a Christian to distinguish false statements from true.