John Chrysostom — as excerpted in the Catena Aurea on John 10:14-21

“(Hom. lx. 2) What wonder that these should hear My voice, and follow Me, when others are waiting to do the same. Both these flocks are dispersed, and without shepherds; for it follows, And they shall hear My voice. And then He foretells their future union: And there shall be one fold and one Shepherd.”