Abdullah bin Abi Musa narrates: Mudrik (the narrator is unsure; perhaps the words are:) Ibn Mudrik sent me to Sayyidah Aishah (may Allah be pleased with her) so that I could ask her about some matters. The narrator says: I came to her, and at that time she was offering the forenoon (Duha) prayer. I thought: I will sit until she finishes. The people said: "That will be a long while!" So I said to her doorkeeper: "How should I seek permission to enter upon her?" That man said: "Say: 'Peace be upon you, O Prophet, and the mercy of Allah and His blessings; peace be upon us and upon the righteous servants of Allah; peace be upon the Mothers of the Believers (the narrator is unsure; perhaps the words are:) the wives of the Prophet (peace and blessings be upon him); as-salamu alaykum.'" After this, the narrator mentioned the full hadith.
Imam Ahmad recorded it, and its narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 12813