The Homilies of St. John Chrysostom on the Gospel According to St. John
"Now there is at Jerusalem a sheep pool, called in the Hebrew tongue Bethesda, having five porches. In these lay a great multitude of impotent folk, of halt, blind, withered, waiting for the moving of the water." (John 5:2-3)
What manner of cure is this? What mystery doth it signify to us? For these things are not written carelessly, or without a purpose, but as by a figure and type they show in outline things to come, in order that what was exceedingly strange might not by coming unexpectedly harm among the many the power of faith. What then is it that they show in outline? A Baptism was about to be given, possessing much power, and the greatest of gifts, a Baptism purging all sins, and making men alive instead of dead. These things then are foreshown as in a picture by the pool, and by many other circumstances. And first is given a water which purges the stains of our bodies, and those defilements which are not, but seem to be, as those from touching the dead, those from leprosy, and other similar causes; under the old covenant one may see many things done by water on this account. However let us now proceed to the matter in hand.