John Chrysostom — as excerpted in the Catena Aurea on John 1:24-28

“(Hom. xvi. [al. xv.] 3) As if he said, Do not think that every thing is contained in my baptism; for if my baptism were perfect, another would not come after me with another baptism. This baptism of mine is but an introduction to the other, and will soon pass away, like a shadow, or an image. There is One coming after me to establish the truth: and therefore this is not a perfect baptism; for, if it were, there would be no room for a second: and therefore he adds, Who is made before me: i. e. is more honourable, more lofty.”