Hakam bin A'raj says that once I went to the service of Sayyiduna Ibn Abbas (may Allah be pleased with them both) at the House of Siqayah. He was sitting, leaning on his cloak. I asked him to tell me something about the Day of Ashura. He said: In what regard are you asking about it? I said: Regarding fasting, that is, on which day should I fast? He said: When you see the crescent of Muharram, keep counting its days. When the morning of the ninth day comes, then fast. I asked: Did the Prophet (peace and blessings be upon him) fast in this way? He said: Yes.