Saeed bin Khalid says that once I went to Abu Salamah (may Allah be pleased with him), he brought butter and a bunch of dates for us. Suddenly, a fly fell into the food. He dipped it with his finger. I said to him, "Uncle! What are you doing?" He said, "Abu Saeed Khudri (may Allah be pleased with him) narrated to me this hadith of the Prophet (peace and blessings be upon him): In one wing of the fly there is poison and in the other there is cure. So if a fly falls into the food, dip it well in it, because it puts the wing with poison first and keeps the wing with cure behind."