A.T. Robertson Commentary John 3:28

"Ye yourselves bear me witness, that I said, I am not the Christ, but, that I am sent before him." — John 3:28 (ASV)

I said (ειπον). As in 1:20,23. He had always put Jesus ahead of him as the Messiah (1:15).

Before him (εμπροσθεν εκεινου). "Before that one" (Jesus) as his forerunner simply.

I am sent (απεσταλμενος ειμ). Periphrastic perfect passive indicative of αποστελλω.