A.T. Robertson Commentary John 7:28

"Jesus therefore cried in the temple, teaching and saying, Ye both know me, and know whence I am; and I am not come of myself, but he that sent me is true, whom ye know not." — John 7:28 (ASV)

And I am not come of myself (κα απ' εμαυτου ουκ εληλυθα). Κα here="and yet." Jesus repeats the claim of verse 17 and also in 5:30; 8:28; 12:49; 14:10.

Whom ye know not (ον υμεις ουκ οιδατε). Jesus passes by a controversy over the piece of popular theology to point out their ignorance of God the Father who sent him. He tersely agrees that they know something of him. Jesus says of these Jews that they know not God as in 8:19,55.