Revelation 2:17

He that hath an ear, let him hear what the Spirit saith to the churches. To him that overcometh, to him will I give of the hidden manna, and I will give him a white stone, and upon the stone a new name written, which no one knoweth but he that receiveth it.

On the first sentence, see under Revelation 2:7, and also regarding "him that overcometh."

I will give of the hidden manna ... The great feasts in the idol-temples were nothing to be compared to the feast of one who eats of "the bread of life" (John 6:35). John remembered the words of Jesus who in that passage identified himself as the true manna that came down from God out of heaven. It is here called "hidden" because it was a secret unknown to the pagan world of the community to which Revelation was written. Finding some reference to the Hebrew myth about a literal pot of manna in this is ridiculous. As Bruce said, "This is another expression meaning eternal life."[73] Many of the other expressions similarly used, such as the white stone, also have exactly that same meaning.

White stone ... It is not necessary to find the meaning of this in ancient superstitions. Small pebbles (not necessarily white) were used as tickets to public functions, especially feasts; and what is meant is simply that the ones who overcome shall receive, "a ticket of admission to the heavenly banquet, a very permanent ticket to an eternal feast."[74] The reference to the new name known only to the recipient ... "The idea is conveyed that outside the Christian experience no one can really know what God is, or what he gives. The redeemed and victorious alone understand what it means to belong to God."[75] Regarding the stone's being white, Cox said that it was, "not the black stone of their condemnation, but a white stone to their exoneration, admitting them to the secret places of the Most High."[76]

[73] F. F. Bruce, op. cit., p. 639.

[74] G. B. Caird, op. cit., p. 42.

[75] James Moffatt, op. cit., p. 359.

[76] Frank L. Cox, According to John (Austin, Texas: Firm Foundation Publishing House, 1948), p. 176.