{That which ye know not} (ho ouk oidate). Cf.  Ac 17:23 .
"You know whom to worship, but you do not know him" (Westcott).
The Samaritans rejected the prophets and the Psalms and so cut
themselves off from the fuller knowledge of God. {We} (h(886d)eis).
We Jews. Jesus is a Jew as he fully recognizes ( Mt 15:24 ).
{That which we know} (ho oidamen). Neuter singular relative as
before. The Jews, as the chosen people, had fuller revelations of
God ( Ps 147:19f.  Ro 9:3-5 ). But even so the Jews as a whole
failed to recognize God in Christ ( 1:11,26  7:28 ). {For
salvation is from the Jews} (hoti h(8820)s(9374)(8872)ia ek t(936e) Ioudai(936e)
estin). "The salvation," the Messianic salvation which had long
been the hope and guiding star of the chosen people ( Lu
1:69,71,77  Ac 13:26,47 ). It was for the whole world ( Joh
3:17 ), but it comes "out of" (ek) the Jews. This tremendous
fact should never be forgotten, however unworthy the Jews may
have proved of their privilege. The Messiah, God's Son, was a
Jew.