John 1:18

θεὸν οὐδεὶς ἑώρακεν … ἐξηγήσατο. This statement, “God no one has ever seen,” is probably suggested by the words διὰ Ἰησοῦ χριστοῦ. The reality and the grace of God we have seen through Jesus Christ, but why not directly? Because God, the Divine essence, the Godhead, no one has ever seen. No man has had immediate knowledge of God: if we have knowledge of God it is through Christ.

A further description is given of the Only Begotten intended to disclose His qualification for revealing the Father in the words ὁ ὢν εἰς τὸν κόλπον τοῦ πατρός. Meyer supposes that John is now expressing himself from his own present standing point, and is conceiving of Christ as in His state of exaltation, as having returned to the bosom of the Father. But in this case the description would not be relevant. John adds this designation to ground the revealing work which Christ accomplished while on earth (ἐξηγήσατο, aorist, referring to that work), to prove His qualification for it. It must therefore include His condition previous to incarnation. ὁ ὤν is therefore a timeless present and εἰς is used, as in Mark 13:16; Acts 8:40, etc., for ἐν. εἰς τὸν κόλπον, whether taken from friends reclining at a feast or from a father's embrace, denotes perfect intimacy. Thus qualified, ἐκεῖνος ἐξηγήσατο “He” emphatic, He thus equipped, “has interpreted” what? See John 8:32; or simply, as implied in the preceding negative clause, “God”. The Scholiast on Soph., Ajax, 320, says, ἐξήγησις ἐπὶ θείων, ἑρμηνεία ἐπὶ τῶν τυχόντων, Wetstein.