Muwatta Malik, Book 53, Hadith 8 (USC-MSA) ⓘ
Yahya related to me from Malik that he heard that when one entered an unoccupied house, one should say, "Peace be upon us and on the slaves of Allah, who are salih." (As-salamu alayna wa ala ibadillahi's-saliheen).O
وَحَدَّثَنِي عَنْ مَالِكٍ أَنَّهُ بَلَغَهُ إِذَا دُخِلَ الْبَيْتُ غَيْرُ الْمَسْكُونِ يُقَالُ السَّلاَمُ عَلَيْنَا وَعَلَى عِبَادِ اللَّهِ الصَّالِحِينَ .
also referenced under: Book 53, Hadith 1765 (In-Book)