Umar came to the Prophet ﷺ while he was in an upper chamber of his and said, "Peace be upon you, Messenger of Allah. Peace be upon you. May Umar enter?"
حدثنا أسود حدثنا الحسن يعني ابن صالح عن أبيه عن سلمة بن كهيل عن سعيد بن جبير
جاء عمر إلى النبي ﷺ وهو في مشربة له فقال السلام عليك يا رسول الله السلام عليك أيدخل عمر
Its isnad is sahih. Salih bin Salih bin Hayy (the father of Hasan bin Salih) is trustworthy trustworthy, as Ahmad said, and the compilers of the six books narrated from him. The hadith is in Majma al-Zawaid 8:44, where it is said, Ahmad narrated it, and its men are the men of sahih. See also what came before in the Musnad of Umar, 222. Al-Mashrubah, with the ra doubled and pronounced with a "u" sound.