The Messenger of Allah ﷺ used to separate the witr from the preceding two units of prayer with a salutation, and he would let us hear it.
كان رسول الله ﷺ يفصل بين الوتر والشفع بتسليمة، ويسمعناها.
Imam Ahmad narrated it (5461), saying, Itaab bin Ziyad told us, Abu Hamza, meaning Sukkari, told us, from Ibrahim, meaning Saigh, from Nafi, from Ibn Umar, and he mentioned it. Its chain of transmission is hasan. Itaab bin Ziyad Khurasani is "truthful," Ibn Majah narrated from him. Ibrahim Saigh is Ibn Maymun Marwazi, also "truthful," and Bukhari narrated from him with a suspended chain. As for Abu Hamza, he is Muhammad bin Maymun Sukkari, a trustworthy and virtuous man among the narrators accepted by the whole community.Ibn Hibban graded it sahih (2435), narrating it through Itaab bin Ziyad with the same wording, except that he said "with a single tasleem," and I believe this is a corruption. Tabarani also narrated it in Al-Awsat (757) through Itaab bin Ziyad, and in it he said "with a tasleema" using the ta marbuta indicating a single occurrence.Haythami erred in Al-Majma (3463) when he said, "In it is Ibrahim bin Saeed, who is daif," after attributing it to Tabarani in Al-Awsat, even though Tabarani himself explicitly stated that it was Ibrahim Saigh and said, "No one narrated this hadith from Ibrahim Saigh except Abu Hamza Sukkari." Perhaps he confused Ibrahim Saigh with Ibrahim bin Saeed Madani, Abu Ishaq, who is among the narrators of Abu Dawud and is of "unknown status."As for Tabarani's statement, "No one narrated this hadith from Ibrahim except Abu Hamza Sukkari," this is not a discrediting flaw, since Abu Hamza Sukkari was among the foremost companions of Ibrahim Saigh, as Nasai and others explicitly stated.On this subject there is also what was narrated from Anas , "that the Prophet ﷺ used to give a single tasleem." Tabarani narrated it in Al-Awsat. Majma Bahrayn (878), from Muaz, Abdullah bin Abdul-Wahhab told us, Abdul-Wahhab bin Abdul-Majid Thaqafi told us, from Humayd, from Anas, and he mentioned it. Bayhaqi also narrated it (2/179) through Abdullah bin Abdul-Wahhab.Tabarani said, "No one attributed it as a raised hadith from Humayd except Abdul-Wahhab." I say, his being the sole narrator does not harm the report, for he is trustworthy and among the narrators of the two sahih collections. The Hafiz said in Al-Diraya (p.90), "Its narrators are trustworthy." Zaylai mentioned it in Nasb Raya (1/433-434) by way of Bayhaqi and remained silent about it.However, Abdul-Wahhab was contradicted regarding the raised attribution, for Malik bin Anas and Abu Khalid Ahmar reported it from Humayd as an action of Anas himself, not as a statement from the Prophet. See Ibn Abu Shayba (1/334-338).As for Bazzar, in Kashf Astar (566), he narrated it from Muhammad bin Abdullah Makhzumi, Yunus bin Muhammad told us, Jareer bin Hazim told us, from Ayub, from Anas, who said, "The Messenger of Allah ﷺ, Abu Bakr, and Umar
used to open the recitation with 'Praise be to Allah, Lord of the worlds,' and they would give the tasleem with full completion." In it is Ayub, who is Sakhtiyani, and he did not hear from Anas nor did he see him, as Ibn Abdul-Barr said in Al-Tamhid (16/189), and he said, "Abu Bakr Bazzar and others said, 'Nothing sound has been established from the Prophet regarding a single tasleem,'" meaning from the standpoint of the chain of transmission, end of quote.Haythami, in Majma al-Zawaid (2878), was content to say, "Bazzar and Tabarani narrated it in Al-Kabir and Al-Awsat, and its narrators are the narrators of the sahih collections."On this subject there are other hadiths from Ibn Abbas, Salama bin Akwa, Samura bin Jundab, and Sahl bin Saad, but all of them are daif. See their sourcing in Al-Tahqiq (2/287) and Nasb Raya (1/433).