Kuraib narrates: Abdullah bin Abbas (may Allah be pleased with them both) and some other companions of the Prophet (may Allah bless him and grant him peace) sent me to Umm Salamah (may Allah be pleased with her) to ask her which days the Prophet (may Allah bless him and grant him peace) used to fast most often. Umm Salamah (may Allah be pleased with her) replied: On Saturday and Sunday. I returned to them and informed them about this, but they did not accept it. All of them got up and went themselves to Umm Salamah (may Allah be pleased with her) and said: We had sent this person to you to ask about this matter, and he has reported that you said this. Umm Salamah (may Allah be pleased with her) said: He has spoken the truth; the Prophet (may Allah bless him and grant him peace) used to fast most often on Saturday and Sunday. The Prophet (may Allah bless him and grant him peace) used to say: These two days are the festivals of the polytheists (they eat and drink on these days), so I wish to act contrary to them.