BabylonianTalmud, Sanhedrin 98a

R. Joshua b. Levi met Elijah standing by the entrance of R. Simeon b. Yohai's tomb. He asked him: “Have I a portion in the world to come?” He replied, “If this Master desires it.” R. Joshua b. Levi said, “I saw two, but heard the voice of a third.” He then asked him, “When will the Messiah come?” “Go and ask him himself,” was his reply. “Where is he sitting?” “At the entrance.” “And by what sign may I recognize him?” “He is sitting among the poor lepers: all of them untie [them] all at once, and re-bandage them together, whereas he unties and re-bandages each separately, [before treating the next], thinking, should I be wanted, [it being time for my appearance as the Messiah] I must not be delayed [through having to bandage a number of sores].” So he went to him and greeted him, saying, “Peace upon you Master and Teacher.” “Peace upon you, O son of Levi,” he replied. “When will you come, Master?” he asked. “Today,” was his answer. On his returning to Elijah, the latter inquired, “What did he say to you?” “Peace upon you, O son of Levi,” he answered. Thereupon he (Elijah) observed, “He thereby assured you and your father of (a portion in) the world to come.” “He spoke falsely to me,” he rejoined, “stating that he would come today, but has not.” He (Elijah) answered him: “This is what he said to you. Today if you will hear his voice.” [Soncino translation]