Musnad Ahmad 32:466

'Abd al-Razzaq narrated to us, Ma'mar informed us, from Thabit al-Bunani, from Anas, or someone else, that the Messenger of Allah (peace and blessings of Allah be upon him) sought permission to enter upon Sa'd ibn 'Ubadah. He said: "Peace be upon you and the mercy of Allah." Sa'd said: "And upon you be peace and the mercy of Allah," but the Prophet (peace and blessings of Allah be upon him) did not hear him. He repeated the greeting three times, and Sa'd responded to him three times, but he did not hear him. So the Prophet (peace and blessings of Allah be upon him) turned back, and Sa'd followed him. He said: "O Messenger of Allah, may my father and mother be sacrificed for you, you did not utter a greeting but that it reached my ears, and I responded to you, but you did not hear me. I wanted to receive more of your greetings and blessings." Then he brought him into the house and offered him raisins. The Prophet of Allah (peace and blessings of Allah be upon him) ate. When he finished, he said: "May the righteous eat your food, may the angels send blessings upon you, and may the fasting ones break their fast with you."