Hakam bin A'raj says: I went to Sayyiduna Abdullah bin Abbas (may Allah be pleased with him), while he was sitting leaning near the well of Zamzam. I also sat with him; he was the best companion. I asked: Tell me about the Day of Ashura. He said: Which aspect of it do you want to ask about? I said: About the fasting of that day. He said: When you see the crescent of the month of Muharram, keep counting the dates; when the morning of the 9th of Muharram comes, fast on that day. I asked: Did Muhammad (peace and blessings be upon him) also fast in this way? He said: Yes.