It was recorded by Muslim, Abū ʿAwānah, Abū Dāwūd, al-Ṭaḥāwī, and Aḥmad. Muslim and Abū ʿAwānah likewise transmit it through the narration of Ibn ʿUmar, while Abū ʿAwānah also relates it from Ibn ʿAbbās.
This pattern is further supported by another hadith of Ibn ʿUmar: A man asked the Messenger of Allah ﷺ about the night prayer, and he replied, “The night prayer is offered two by two; when one of you fears that dawn is about to break, let him pray a single rakʿah, which will make what he has already prayed an odd number.”
The report is related by Mālik, al-Bukhārī, Muslim, and Abū ʿAwānah, who add: Someone asked Ibn ʿUmar, “What does ‘two by two’ mean?” He answered, “That one gives salām after every pair of rakʿahs.”
In another wording preserved by Mālik and al-Bukhārī it says that ʿAbdullāh ibn ʿUmar used to give salām between the single rakʿah and the two rakʿahs of witr so that he could attend to some need.
The explanation just cited from Ibn ʿUmar is also transmitted by Aḥmad as a marfūʿ report embedded in the text of the hadith itself. However, the chain includes ʿAbd al-ʿAzīz ibn Abī Rawād, who is reliable yet sometimes errs, as stated in al-Taqrīb. I therefore fear that he may have erred in attributing it to the Prophet ﷺ. Allah knows best. ⦗104⦘