Imam Abu Bakr, may Allah have mercy on him, says that the ahadith of the Noble Prophet (peace and blessings be upon him) in which he forbade fasting on Friday alone, except if one fasts a day before Friday or a day after it, contain evidence that the Prophet (peace and blessings be upon him) permitted fasting on Saturday, provided that one fasts on Friday before it or on the day after it (Sunday).

Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that I heard the Messenger of Allah (peace be upon him) say: "Friday is a day of Eid, so do not fast on the day of Friday unless you fast a day before it or a day after it." Imam Abu Bakr (may Allah have mercy on him) says that in this way, the Noble Prophet (peace be upon him) permitted fasting on Saturday if the fasting person also fasted on Friday before it.

The freed slave of Sayyiduna Ibn Abbas (may Allah be pleased with them both), Kuraib, narrates that Sayyiduna Ibn Abbas (may Allah be pleased with them both) and some of the companions (may Allah be pleased with them) of the Messenger of Allah (peace and blessings of Allah be upon him) sent me to Sayyidah Umm Salamah (may Allah be pleased with her) to ask her which days the Messenger of Allah (peace and blessings of Allah be upon him) used to fast frequently. She replied that he used to fast frequently on Saturday and Sunday. So I returned and informed them of this, but it was as if they did not accept this statement. All of them got up and went to her and said, "We sent him to you to ask you about this issue, and he has told us that you gave this answer." She replied, "He has spoken the truth. Indeed, the Messenger of Allah (peace and blessings of Allah be upon him) used to fast most often on Saturday and Sunday, and he used to say: 'These two days are the festival days of the polytheists (they eat and drink on them), and I wish to oppose them (by fasting on these days).’"