In the period before Prophet Muhammad (pbuh) called the interregnum, both oracles and some scholars gave the good news about Allah’s Messenger’s coming. Some of them mentioned him in their poems; some extended this good news to next centuries through their letters. We will try to recount some examples of them here.
First: One of the kings of Yemen, Tubba, saw the qualities of Allah’s Messenger in old books and professed belief. He recited this poem:
“I affirm the messengership of Ahmad (pbuh). If I were to reach his time, I would be his vizier and cousin. (In other words, I would be like Ali)” Second: Famous Quss Ibn Saida was one of the most renowned and important orators and he was a monotheist, aware of the truths. With the following poem, he proclaims the prophethood of Muhammad (PBUH) before he was sent:
“He sent Ahmad (PBUH) as the most auspicious of those who were sent and of the prophets. May Allah show His mercy on him as long as caravans set off for him and as long as this is encouraged.” Third: One oftheancestors of Allah’s Messenger (PBUH), Ka’b Ibn Luayy, declares, through inspiration, the coming of the Prophet:
“All of a sudden Prophet Muhammad (PBUH) will come and give the truthful news.” Fourth: Sayf Ibn Ziyazan, one of the kings of Yemen, saw the qualities of Allah’s Messenger (PBUH) in the old scriptures, believed in and aspired for him. When the Prophet’s grandfather, Abdulmuttalib, went to Yemen with the caravans of Quraysh, Sayf Ibn Ziyazan called for them and told them:
“A child is to be born in Hejaz. There is a sign like a seal between his shoulders. This child will be an imam for all people.” Later, he secretly called for Abdulmuttalib and miraculously gave him the news of the Prophet before his birth with these words: “You are the grandfather of that child.” 
Fifth: When the mother of the believers,Khadijah (may Allah be pleased with her), told her cousin, Waraqa bin Nawfal at the beginning of the revelation that Allah’s Messenger got worried, Waraqa said “Send him to me.” Allah’s Messenger went to Waraqa and explained the situation he was in during the coming of revelation. Waraqa said:
“Do not worry; this state is revelation. Good news for you! You are the expected prophet. Jesus gave the good news of you.” Sixth: Before the Prophet was sent, a knowledgeable person named Asqalani’l-Himyari would ask the people of Quraysh whenever he saw them: “Is there anyone who claims prophethood among you?”and thepeople of Quraysh would say “No.” Later, after the duty of prophethood was assigned, he asked again, and they replied, “Yes, someone is claiming prophethood.” Asqalani said:
“Behold, the world has been expecting him.” Seventh: One of the Christian scholars, Ibnu’l Ala gave the news of the Prophet before the duty of prophethood was given and before he saw the Prophet. Later he came and saw the Prophet. He said:
“I saw your qualities in the Gospel and professed faith. Ibn Maryam (Jesus) gave the good news of your coming in the Gospel.” Eighth: The King of Abyssinia, Negus, said:
“Instead of this kingdom, if only, I were the servant of Prophet Muhammad (PBUH)! That servanthood is superior to this kingdom.” Now, after those scholars who gave news of the unknown through divine inspiration, we will mention the good news given by oracles who inform people of the unknown through spirits and jinn; we will retell only a few examples out of the many mentioned in the books of history and the Prophet’s biographies.
First: A well-known oracle named Shiqq with only one eye, one hand, one foot, almost like a half-human gave the good news of the Prophet’s coming many times before the Prophet was sent. 
Second: It is the news given by a renowned oracle from Damascus, Satih, a hideous-looking man with his face in his chest, with no bones, a body as if with no organs, who lived for a long time. He was well-known among the people of that time with the news of the unknown that he gave correctly. Furthermore, Kisra, the King of Persia, sent Muyzan, a scholar and an envoy of his, to Satih in order to ask about a strange dream he had at the night of the Prophet’s birth in which he saw his palace’s fourteen towers fall down. Satih said to the envoy: “Fourteen people will rule your country and then your kingdom will be ruined. And someone will come and proclaim a religion. That will abolish your religion and state.” andhe thus informed Kisra of the interpretation of his dream. As is seen, Satih gave the news of the Prophet’s coming. 
As is explained in history books and the biographies of the Prophet, among oracles such renowned ones as Sawad Ibn Qaribi’d-Dawsi, Hunafir, Af’asiya Najran, Jizl Ibn Jizli’l-Kindi, Ibn Kalasati’d-Dawsi and Fatima Bint Numan an-Najariyya announced that the Prophet of the end of time would come and he would be Muhammad (PBUH). 
Moreover, one of the relatives of Uthman bin Afwan (may Allah be pleased with him), Sa’d Bint Kurayz, received the news of the prophethood of Allah’s Messenger through soothsaying. At the very beginning of Islam, he said to Uthman bin Afwan “Go and profess faith.” Upon this advice, Uthman bin Afwan went and professed belief and thus had the honor to be one of the first Muslims. Sa’d tells this event in the following poem:
“Allah granted Uthman salvation through a word I said to him. The one who brings to the truth is Allah alone.”Furthermore, just like oracles, the jinn called ‘hatif’ who could not be seen in person but whose voice could be heard, gave the news of the Prophet’s coming many times. For example, one of these creatures called out to Zayab Ibn al Haris in the following way and became a means for his and someone else’s accepting Islam:
“O Zayab, o Zayab! Listen to the strangest of the strangest: Muhammad was sent with a book; he is calling the people of Mecca, but they do not listen to him.” Similarly, another hatif called out to Samia bin Qarrat al Ghatafani like that and caused some people to have faith:
“The truth came and scattered light. The falsity, though, is ruined, uprooted.” The incidents of these hatifs’ giving good news and informing are quite renowned and many in number.
Besides, just as oracles and hatifs gave the news of the Prophet’s coming, so, too, did some animals sacrificed for the idols heralded his prophethood.
For instance, the idol of the Mazan Tribe called out “This appointed Prophet brought a truthful book revealed to him.”  and thus informed people of Muhammad’s prophethood (PBUH).
Another example is the famous event that became a means for Abbas Ibn Mardas’ accepting Islam: He had an idol named Dimar. That idol once made such an utterance: “Before Muhammad came, I was worshipped. Now that Muhammad’s call came, this aberration cannot prevail any longer.”
Before Islam, Umar Ibn Khattab (may Allah be pleased with him) heard from an animal sacrificed for an idol:
“O those who sacrifice an animal! Something important is happening; a man is saying with a clear language ‘La ilaha illa Allah’ (there is no God but Allah)” To sum up, there are many such incidences as the ones mentioned above. They have been acquiesced and recounted by trustable books. Many oracles, scholars, hatifs and even idols and sacrificed animals gave the news of Muhammad’s prophethood (PBUH), which in turn acted as a medium for certain people’s faith. Similarly, on some stones, graves and gravestones, such writings as “Muhammad is the corrector and trustable.” in old scriptswere found and via those some people grasped faith.  Indeed, ‘Muhammad’ mentioned in the writing “Muhammad is the corrector and trustable.” refers to Allah’s Messenger (PBUH). This is because before him, close to his time, there were only seven people with the name Muhammad. And none of those seven men were worthy of the quality “the corrector and trustable.”
Ibn Kathir, al-Bidaya wa’n-Nihaya, 2:166; Qadi Iyad, ash-Shifa, 1:363; Ali al-Qari, Sharhu’sh-Shifa, 1:740; al-Hakim, al-Mustadrak, 2:388; Nabhani, Hujjatullah ala’l-Alamin, 138.
Suyuti, al-Fathu’l-Kabir, 2:133; Ibni Kathir, al-Bidaya wa’n-Nihaya, 2:230; Qadi Iyad, ash-Shifa, 1:363; Ali al-ari, Sharhu’sh-Shifa, 1:740; Tabarani, al-Mu’jamu’l-Kabir, 12:1254; Bayhaqi, Dalailu’n-Nubuwwa: 2:101; Abu Nuaym, Dalailu’n-Nubuwwa, 1:105.
Ibn Kathir, al-Bidaya wa’n-Nihaya, 2:244; Qadi Iyad, ash-Shifa, 1:364; Ali al-Qari, Sharhu’sh-Shifa, 1:740; Abu Nuaym, Dalailu’n-Nubuwwa, 1:89-90.
 Ibn Kathir, al-Bidaya wa’n-Nihaya, 2:328; Qadi Iyad, ash-Shifa, 1:343; Ali al-Qari, Sharhu’sh-Shifa, 1:740; al-Hakim, al-Mustadrak, 2:388; Abu Nuaym, Dalailu’n-Nubuwwa, 1:95-96; Halabi, as-Siratu’l-Halabiya, 1:187.
Bukhari, Badu’l-Wahy: 3; Anbiya: 21; Ta’bir: 1; Musnad (tahkik: Ahmed Şâkir), 4:304, no. 2846; Kadi Iyaz, ash-Shifa, 1:363; Ali al-Kari, Sharhu’sh-Shifa, 1:743; Ajurri, ash-Sharia, 443; Abu Nuaym, Dalailu’n-Nubuwwa, 1:217.
 Kadi Iyaz, ash-Shifa, 1:363; Ali al-Kari, Sharhu’sh-Shifa, 1:742; Nabhani, Hujjatullah ala’l-Alamin, 140.
 Ali al-Kari, Sharhu’sh-Shifa, 1:744; Nabhani, Hujjatullah ala’l-Alamin, 121, 208
 Kadi Iyaz, ash-Shifa, 1:365 Nabhani, Hujjatullah ala’l-Alamin, 115; Bayhaki, Dalailu’n-Nubuwwa: 2:285.
 Kadi Iyaz, ash-Shifa, 1:364; Ali al-Kari, Sharhu’sh-Shifa, 1:747; Nabhani, Hujjatullah ala’l-Alamin, 168-172; Abu Nuaym, Dalailu’n-Nubuwwa, 1:123, 125.
 Ibn Kasir, al-Bidaya wa’n-Nihaya, 2:355-369; Bayhaki, Dalailu’n-Nubuwwa: 2:126,129; Abu Nuaym, Dalailu’n-Nubuwwa, 1:125; Kadi Iyaz, ash-Shifa, 1:365; Ali al-Kari, Sharhu’sh-Shifa, 1:747; Suyuti, al-Hasaisu’l-Kubra, 1:128-130.
 Ibn Kasir, al-Bidaya wa’n-Nihaya, 2:335; Bayhaki, Dalailu’n-Nubuwwa: 2:248; Abu Nuaym, Dalailu’n-Nubuwwa, 1:125; Kadi Iyaz, ash-Shifa, 1:365; Ali al-Kari, Sharhu’sh-Shifa, 1:747; Suyuti, al-Hasaisu’l-Kubra, 1:128-130; al-Haysami, Majmau’z-Zawaid, 8:248-249, 51.
 Suyuti, al-Hasaisu’l-Kubra, 1:258.
Halabi, as-Siratu’l-Halabiya, 1:335-337; Suyuti, al-Khasaisu’l-Kubra, 1:358; Nabhani, Hujjatullah ala’l-Alamin, 181.
 Ali al-Qari, Sharhu’sh-Shifa, 1:748; Suyuti, al-Khasaisu’l-Kubra, 1:252.
 Bayhaqi, Dalailu’n-Nubuwwa: 2:255; Halabi, as-Siratu’l-Halabiya, 1:325; Ibn Kathir, al-Bidaya wa’n-Nihaya, 2:337; al-Haythami, Majmau’z-Zawaid, 8:242; Ali al-Qari, Sharhu’sh-Shifa, 1:747; Suyuti, al-Khasaisu’l-Kubra, 1:252-271.
ash-Shifa (Tahqiq: M. Emin Kara Ali and…), 1:598; al-Haythami, Majmau’z-Zawaid, 8:246; Ibn Kathir, al-Bidaya wa’n-Nihaya, 2:341-342; Bayhaqi, Dalailu’n-Nubuwwa: 1:118.
Bukhari, Manaqibu’l-Ansar: 35; as-Sa’ati, al-Fathu’r-Rabbani, 20:2030.
 Qadi Iyad, ash-Shifa, 1:467; Ali al-Qari, Sharhu’sh-Shifa, 1:749; Halabi, as-Siratu’l-Halabiya, 1:354.
 Halabi, as-Siratu’l-Halabiya, 1:131-134