For the first sentence, He who has an ear … churches, see the comments at 2.7, 11.
To him who conquers : see 2.7, 11. As elsewhere, the exclusively masculine To him can be rendered inclusive by using the plural, “To those who conquer,” or the indefinite, “Whoever conquers.”
I will give him some of the hidden manna: this simple promise reflects a popular belief concerning the jar full of manna (the food the Hebrews ate during their forty years in the wilderness) that had been stored in the Covenant Box (Exo 16.32-34; see Heb 9.4). It was believed to be the jar that had been hidden by Jeremiah in a cave on Mount Nebo after the destruction of the Temple in 586 B.C. (2 Maccabees 2.4-8), where it would remain until the Messianic age, when God would once more feed the people with it. It is impossible to incorporate all this information in the text itself, and a cultural footnote may be added, or else the word can be explained in a word list. However, in languages that cannot use a passive form for hidden, translators may employ a general agent and say “the manna that someone (or, they) hid.”
A white stone, with a new name written on the stone: there are several explanations of this white stone. It may have been a charm, an amulet, which was believed to protect the wearer against evil forces, or else something like an invitation card, authorizing the bearer to take part in the (Messianic) banquet. Some take it to have been the stone on which was written the judge’s verdict of acquittal. White was the color of victory (see 19.11, 14). Again, in some languages translators will need to use an indefinite agent with an active verb; for example, “on which they have written a new name.”
It is impossible to decide whether the new name engraved on the white stone was the name of Christ himself, the name of God, or else, which is more likely, the new name the victorious person received, which was known by no one else and enabled that person to take part in the Messianic banquet. Whatever the interpretation, a translation should say nothing more than “a new name,” without indicating whose it was. The final sentence of this verse may be restructured as follows: “Only the person who receives this stone will know this name.”
Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on The Revelation to John. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .