And he that saw it bare record, and his record is true. — Comp. John 1:7. It may be better to render the word here, as elsewhere, by “witness,” in order that we may get the full force of its frequent recurrence. The writer speaks of himself in the third person (comp. Introduction, p. 375), laying stress upon the specially important fact that it was an eye-witness — “he that saw it” — who testified to the fact, and one who therefore knew it to be true. The word rendered “true” in this clause is the emphatic word for “ideally true,” which is familiar to the readers of this Gospel. (Comp. Note on John 1:9.) It answers to the idea of what evidence should be, because it is the evidence of one who himself saw what he witnesses.
And he knoweth that he saith true, that ye might believe. — The witness was ideally true, and therefore the things witnessed were actually true. He cannot doubt this, and he testifies it in order that others may find in these truths ground for, and the confirmation of, their faith.