The Words of the Prophets Are Written on the Subway Walls (Shoftim, 5785)

(18) I will raise up for them from among their own people a prophet like yourself, in whose mouth I will put My words and who will speak to them all that I command; (19) and anybody who fails to heed the words [the prophet] speaks in My name, I Myself will call to account. (20) But any prophet who presumes to speak in My name an oracle that I did not command to be uttered, or who speaks in the name of other gods—that prophet shall die.” (21) And should you ask yourselves, “How can we know that the oracle was not spoken by יהוה?”— (22) if the prophet speaks in the name of יהוה and the oracle does not come true, that oracle was not spoken by יהוה; the prophet has uttered it presumptuously: do not stand in dread of that person.

(Ibid.) "and I shall place My words in his mouth": I shall do this, but I shall not speak to him face to face. ("And I shall place My words in his mouth":) From now on, realize that the holy spirit has been placed in the mouth of the prophets.

(7) But just listen to this word that I address to you and to all the people: (8) The prophets who lived before you and me from ancient times prophesied war, disaster, and pestilence against many lands and great kingdoms. (9) So if a prophet prophesies good fortune, then only when the word of the prophet comes true can it be known that GOD really sent him.”

(1) It is [one] of the foundations of [our] faith that God conveys prophecy to man. Prophecy is bestowed only upon a very wise sage of a strong character, who is never overcome by his natural inclinations in any regard. Instead, with his mind, he overcomes his natural inclinations at all times. He must [also] possess a very broad and accurate mental capacity. A person who is full of all these qualities and is physically sound [is fit for prophecy]. When he enters the Pardes and is drawn into these great and sublime concepts, if he possesses an accurate mental capacity to comprehend and grasp [them], he will become holy. He will advance and separate himself from the masses who proceed in the darkness of the time. He must continue and diligently train himself not to have any thoughts whatsoever about fruitless things or the vanities and intrigues of the times. Instead, his mind should constantly be directed upward, bound beneath [God's] throne [of Glory, striving] to comprehend the holy and pure forms and gazing at the wisdom of the Holy One, blessed be He, in its entirety, [in its manifold manifestations] from the most elevated [spiritual] form until the navel of the earth, appreciating His greatness from them. [After these preparations,] the divine spirit will immediately rest upon him. When the spirit rests upon him, his soul becomes intermingled with the angels called ishim, and he will be transformed into a different person and will understand with a knowledge different from what it was previously. He will rise above the level of other wise men, as [the prophet, Samuel] told Saul [I Samuel 10:6]: "[The spirit of God will descend upon you] and you shall prophesy with them. And you will be transformed into a different person."

§ The Sages taught: After the last of the prophets, Haggai, Zechariah, and Malachi, died, the Divine Spirit of prophetic revelation departed from the Jewish people. But nevertheless, they were still utilizing a Divine Voice, which they heard as a kind of echo of prophecy. One time, a group of Sages were reclining in the loft of the house of Gurya in Jericho, and a Divine Voice was bestowed upon them from Heaven, saying: There is one here who is fit for the Divine Presence to rest upon him as it rested upon Moses our teacher, but his generation is not deserving of this distinction.