Sunan Ibn Majah, Hadith 920 ⓘ
It was narrated that Salamah bin Akwa’ said: “I saw the Messenger of Allah performing the prayer, and he said one Salam.”
حَدَّثَنَا مُحَمَّدُ بْنُ الْحَارِثِ الْمِصْرِيُّ، حَدَّثَنَا يَحْيَى بْنُ رَاشِدٍ، عَنْ يَزِيدَ، مَوْلَى سَلَمَةَ عَنْ سَلَمَةَ بْنِ الأَكْوَعِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ صَلَّى فَسَلَّمَ مَرَّةً وَاحِدَةً .
also referenced under: Book 5, Hadith 973 (In-Book) & Volume 2, Book 5, Hadith 920 (DarusSalam)