When Christ cometh, none knoweth whence he is — This Jewish tradition was true, with regard to his Divine nature: in that respect none could declare his generation. But it was not true with regard to his human nature, for both his family and the place of his birth were plainly foretold.
Related Commentaries of John 7:27
John 7:27
27 Howbeit we know this man whence he is: but when Christ cometh, no man knoweth whence he is.