John Gill Commentary John 4:54

"This is again the second sign that Jesus did, having come out of Judaea into Galilee." — John 4:54 (ASV)

This [is] again the second miracle [that] Jesus did
That is, in that place, in Cana of Galilee; for otherwise, in Jerusalem and Judea, he had done many miracles, between the former and this; see (John 2:23) (3:2) ; and so the following words explain it:

when he was come out of Judea into Galilee ;
this was the first he wrought, after his coming out of Judea into Galilee, this time, and was the second that he wrought in Cana of Galilee; see (John 2:11) .