Rav Huna said: A good person is not shown a good dream and a wicked person is not shown a bad dream; rather, a good person is punished for their relatively few transgressions with bad dreams and a wicked person is rewarded for their relatively few merits with good dreams.
In a long chain of those transmitting this statement, it is said that Rabbi Bizna bar Zavda said that Rabbi Akiva said that Rabbi Panda said that Rav Naḥum said that Rabbi Birayim said in the name of one elder, and who is he, Rabbi Bena’a: There were twenty-four interpreters of dreams in Jerusalem. One time, I dreamed a dream and went to each of them to interpret it. What one interpreted for me the other did not interpret for me, and, nevertheless, all of the interpretations were realized in me, to fulfill that which is stated: All dreams follow the mouth of the interpreter.
With regard to the veracity of dreams, Rabbi Yoḥanan said: One who awakened in the morning and a specific verse happens into their mouth, it is a minor prophecy and an indication that the content of the verse will be fulfilled. Rabbi Yoḥanan also said: Three dreams are fulfilled: A dream of the morning, a dream that one’s fellow dreamed about them, and a dream that is interpreted within a dream. And some say that a dream that is repeated several times is also fulfilled, as it is stated: “And for that the dream was doubled unto Pharaoh twice, it is because the thing is established by God, and God will shortly bring it to pass” (Genesis 41:32).
Rav Yehuda said that Rav said: And, so too, one should be joyful before stating a matter of halakha. Rav Naḥman said: And, so too, one should be joyful before going to sleep, to ensure one will have a good dream.
Rav Yehuda said in the name of Rav: Three matters require a plea for mercy to bring them about: A good ruler, a good year, and a good dream. These three, rulers, years, and dreams, are all bestowed by God and one must pray that they should be positive and constructive. The Gemara enumerates the sources for these cases: A good ruler, as it is written: “The ruler’s heart is in the hand of the Lord as the watercourses: God turns it whithersoever God wills” (Proverbs 21:1). A good year, as it is written: “The eyes of the Lord, thy God, are always upon it, from the beginning of the year even unto the end of the year” (Deuteronomy 11:12). And a good dream, as it is written: “O Lord, by these things people live, and altogether therein is the life of my spirit; wherefore You will recover me [vataḥlimeni], and make me to live” (Isaiah 38:16). Due to their apparent etymological similarity, the word taḥlimeni is interpreted as deriving from the word ḥalom, dream.
העונה יהא שמיה רבא מברך מובטח לו שהוא בן העולם הבא הקורא ק"ש ראוי שתשרה עליו שכינה אלא שאין דורו זכאי לכך
One who answers in a dream: May God's great name be blessed from kaddish is assured that they are one who has a place in the World-to-Come. One who sees oneself reciting Shema in a dream is worthy of having the Divine Presence rest upon them, but their generation is unworthy, and, therefore, the Divine Presence does not actually rest upon them.
One who defecates in a dream, it is a good omen for them as it is stated: “One that is bent down shall speedily be loosed; and one shall not go down dying into the pit, neither shall one's bread fail” (Isaiah 51:14). The Gemara notes that this only applies where one does not wipe and get one's hands dirty.
The tanna who recited mishnayot before Rabbi Yoḥanan taught: One who sees any kind of drink in a dream it is a good omen, except for wine, as there is one who drinks it in a dream and it is a good omen for them, and there is one who drinks it in a dream and it is a bad omen for them. The Gemara elaborates: There is one who drinks wine and it is a good omen for them, as it is stated: “And wine that makes glad the heart of man” (Psalms 104:15), and there is one who drinks it in a dream and it is a bad omen for them, as it is stated: “Give strong drink unto one that is ready to perish and wine unto the bitter in soul” (Proverbs 31:6).
Rabbi Yoḥanan said: One who awakened in the morning and a verse immediately falls into his mouth, it is a minor prophecy. The Sages taught: There are three kings whose appearance in a dream is significant. One who sees David in a dream should expect piety; one who sees Solomon should expect wisdom; and one who sees Ahab should be concerned about calamity.
Similarly: Six matters are good omens for the sick: Sneezing, sweating, diarrhea, a seminal emission, sleep, and a dream. These are all alluded to in Scripture: Sneezing, as it is written: “God's sneezes flash forth light” (Job 41:10), indicating that by means of a sneeze one comes to see the light of the world. Sweat, as it is written: “In the sweat of your face shall you eat bread” (Genesis 3:19). Diarrhea, as it is written: “One that is bent down shall speedily be loosed; and one shall not go down dying into the pit” (Isaiah 51:14). A seminal emission, as it is written: “That he might see his seed, prolong his days” (Isaiah 53:10). Sleep, as it is written: “I should have slept; then had I been at rest” (Job 3:13). A dream, as it is written: “Wherefore You recover me [vataḥalimeni], and make me to live” (Isaiah 38:16); vataḥalimeni is interpreted as etymologically similar to ḥalom, dream.
§ The Gemara relates another story. Rava happened to come to the city of Hagrunya. He decreed a fast, but rain did not come. He said to the local residents: Everyone, continue your fast and do not eat tonight. The next morning he said to them: Whoever had a dream last night, let them say it. Rabbi Elazar of Hagronya said to them: The following was recited to me in my dream. Good greetings to a good master from a good Lord, Who in God's goodness does good for God's people. Rava said: I can learn from this that it is a favorable time to pray for mercy. He prayed for mercy and rain came.
He said before God: Master of the Universe, it is written: “O God, we have heard with our ears, our ancestors have told us, what work You did in their days, in days of old” (Psalms 44:2), but we have not seen it with our own eyes. As soon as he said this, rain came until the gutters of Meḥoza overflowed and poured into the Tigris River. Rava’s father came and appeared to him in a dream and said to him: Is there anyone who troubles Heaven so much to ask for rain out of its season? In his dream, his father further said to him: Change your place of rest at night. He changed his place, and the next day he found that his bed had been slashed by knives.