1 Then the angel showed me the river of the water of life—water as clear as crystal—pouring out from the throne of God and of the Lamb, 2 flowing down the middle of the city’s main street. On each side of the river is the tree of life producing twelve kinds of fruit, yielding its fruit every month of the year. Its leaves are for the healing of the nations. 3 And there will no longer be any curse, and the throne of God and the Lamb will be in the city. His servants will worship him, 4 and they will see his face, and his name will be on their foreheads. 5 Night will be no more, and they will not need the light of a lamp or the light of the sun, because the Lord God will shine on them, and they will reign forever and ever. 6 Then the angel said to me, “These words are reliable and true. The Lord, the God of the spirits of the prophets, has sent his angel to show his servants what must happen soon.”
Pesachim 50aBabylonian Talmud
Incidental to the discussion of leaving Jerusalem and its surrounding area, the Gemara cites expositions of a prophetic passage, including a statement that God will eventually expand the boundaries of Jerusalem. The verse states: “And it shall come to pass on that day that there shall not be light, but heavy clouds [yekarot] and thickness [vekippaon]” (Zechariah 14:6). The Gemara asks: What is the meaning of the expression “yekarot vekippaon”? Rabbi Elazar said: This is the light currently provided by the sun, which is significant [yakar] in this world and insignificant [kafuy] in the World-to-Come, when the moon will shine as brightly as the sun does now and the sun will be seven times brighter than it is currently. Rabbi Yoḥanan said: This expression refers to the tractates of Nega’im and Oholot, which are weighty [yekarim] owing to their difficulty in this world, as they are among the most complex subjects, but will be easy [kefuyin] in the World-to-Come, when people will be much wiser.
Notes and References
"... The second function for olam ha-ba [the world to come], the interpretive one, provided the rabbis with a new hermeneutical tool to read biblical passages that, ostensibly, have nothing to do with reward and punishment. This binary of olam ha-zeh and olam ha-ba is often employed to explain strange or redundant biblical words and phrases. At times, the rabbis situate olam ha-zeh and olam ha-ba as opposites: for example, they would argue, unlike this world where suffering occurs, the next world would be full of pleasure. (b. Pesachim 50a; For other examples of rabbinic texts that contrast olam ha-ba and olam ha-zeh, see especially Leviticus Rabbah 13:3, b. Bava Metzia 85b, and Midrash Psalms 91) At other times, the rabbis use the binary of olam ha-zeh and olam ha-ba to express continuities or foreshadowing: for example, just as there are Torah academies in this world, so too there will be Torah academies in the next world, albeit even greater ones ..."
Greenspoon, Leonard Olam ha-zeh v’olam ha-ba: This World and the World to Come in Jewish Belief and Practice (pp. 94-95) Purdue University, 2017