Sayyidah Umm Tariq (may Allah be pleased with her), who was the freedwoman of Sayyiduna Sa'd (may Allah be pleased with him), narrates: The Prophet (peace and blessings be upon him) came to Sayyiduna Sa'd (may Allah be pleased with him) and sought permission to enter, but Sayyiduna Sa'd (may Allah be pleased with him) remained silent. Then he sought permission again, and Sayyiduna Sa'd (may Allah be pleased with him) remained silent. Then he sought permission once more, and Sayyiduna Sa'd (may Allah be pleased with him) again remained silent. The Prophet (peace and blessings be upon him) turned back, so Sayyiduna Sa'd (may Allah be pleased with him) sent me to him and submitted: "We did not give you permission only because we wanted you to (keep greeting us) more." After this, the narrator mentioned the complete hadith. The complete narration is in the Book of Medicine, in the chapter on fever.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 12754